I have experience with all those sets and they are all good fun to play, I haven't tried a fire/ice combo but have played them seperately (ice/ice and fire/nrg).
I am really enjoying my Grav/Psi at the moment. Gravity has loads of fun, utility powers like wormhole and dimension shift and can really turn the tide in a hectic battle.
Psi is probably the quickest secondary for building domination and in a full team you can get it in no time just by spamming psi dart.
If you choose to go Grav/Psi you can probably do without Aid Self. Once slotted you will have Drain Psyche available in every fight and that gives you really good regen. I'd seriously consider getting Dimension Shift, a lot of people do not like intangible powers but with a bit of practice and knowing when to use it, it can be one of the most useful powers in the whole set.
Whichever you pick, have fun 
Thanks for the reply minutaur, as a dom I just consider that I may need medicine, oh and I'm a badge hunter 
I'll proably use it in times when drain psyche misses. I;m also getting scirocco for end and a lovely pet which will rally help. Sing+guardian+me=:O
As for fire/ice, the mu pet would really hlep there aswell since I would have 4 pets. I just hope I can cope with slow lvling I got vet reward to help a bit.
I'll sort out slots later.
Sorry for double posting, but I've decided to go with grv/psi dom. Here's my build...
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Exported from Ver: 1.7.6.0 of the CoH_CoV Character Builder - (http://sherksilver.coldfront.net/index.php)
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Name: Dr. Psychotica
Level: 50
Archetype: Dominator
Primary: Gravity Control
Secondary: Psionic Assault
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01) --> Lift==> Dmg(1) Dmg(3) Acc(9) Acc(9) Rechg(15)
01) --> Psionic Dart==> Acc(1) Rechg(15)
02) --> Gravity Distortion==> Acc(2) Acc(3) Hold(5) Hold(5) Rechg(11)
04) --> Mind Probe==> Dmg(4) Acc(7) Acc(7) Rechg(11)
06) --> Combat Jumping==> EndRdx(6) DefBuf(31)
08) --> Hurdle==> Jump(8) Jump(50)
10) --> Aid Other==> Heal(10)
12) --> Hasten==> Rechg(12) Rechg(13) Rechg(13)
14) --> Super Jump==> Jump(14)
16) --> Psychic Scream==> Dmg(16) Dmg(17) Dmg(17) Acc(23) Acc(34) Rechg(40)
18) --> Gravity Distortion Field==> Acc(18) Acc(19) Hold(19) Hold(31) Rechg(37) Rechg(46)
20) --> Drain Psyche==> Rechg(20) Rechg(21) Rechg(21) Acc(23) Acc(37) EndMod(37)
22) --> Health==> Heal(22)
24) --> Stamina==> EndMod(24) EndMod(25) EndMod(25)
26) --> Wormhole==> Acc(26) Acc(27) DisDur(27) Rechg(43) Rechg(43) Rechg(43)
28) --> Aid Self==> Heal(28) Heal(29) Heal(29)
30) --> Acrobatics==> EndRdx(30) EndRdx(31)
32) --> Singularity==> Acc(32) Acc(33) Hold(33) Hold(33) Immob(34) Immob(34)
35) --> Psionic Lance==> Dmg(35) Dmg(36) Acc(36) Acc(36)
38) --> Psychic Shockwave==> Dmg(38) Dmg(39) Dmg(39) Acc(39) Acc(40) Rechg(40)
41) --> Power Sink==> Rechg(41) Rechg(42) Rechg(42) EndMod(42)
44) --> Charged Armor==> EndRdx(44) EndRdx(45) EndRdx(45) DmgRes(45) DmgRes(46) DmgRes(46)
47) --> Summon Guardian==> Dmg(47) Dmg(48) Acc(48) Rechg(48) Rechg(50) Rechg(50)
49) --> Super Speed==> Run(49)
---------------------------------------------
01) --> Sprint==> Empty(1)
01) --> Brawl==> Empty(1)
01) --> Domination==> Empty(1)
02) --> Rest==> Empty(2)
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Made this build in 2 minutes so expect mistakes :P
Comments and criticism please
One thing that comes to mind:
Slot Guardian as follows:
Heal Heal Heal Recharge Recharge Recharge.
It's the next best thing to a dedicated thermal out there to keeping you alive.
Also I'd drop the immobs from the singularity - it's very single-minded and after it starts attacking an opponent it will get immobed and held and thrown around - he'll be controlled with just 2 x hold and the natural durations. Switch them for damage.
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I believe that is 2 things that come to mind :P
Anyway I think I agree wasn't sure about the pets does the guardian heal frequently because with my experience with pets they tend to do anything they like and go rambo...
I'd personally put three damage SOs in Mind Probe. It will be your biggest hitter until you reach the later levels.
In that case I'll use the oppertunity of not having to slot the lvl 6, 8 and 10 power to slot it up.
I wouldn't mind seeing some further ideas on Grav/Psi, as I also have one to level up very soon. Would you consider posting your build Minotaur? I have no experience in either set this far, so any advice keenly sought .
I have a level 40 grav/psi dom. The main thing to watch out for is you don't accidentally grab too much aggro using things like wormhole and psi shockwave. Also, you can completely skip stamina if you properly slot drain psyche. You will most probably find /psi to be slightly underpowered until you get psychic shockwave, which really makes up for it.
Don't waste too many slots on Psychic Scream - it's damage is [censored].
Fully slot Wormhole earlier, especially with RECS and ACCS.
@Under Control
Actually, I have never found too much use for Psychic Sream at all. Especially after acquiring Psychic Shockwave it seems utterly pointless.
And this medicine pool thing just makes me shake my head. I most certainly don´t need all the badges on every toon and you will not need it for anything else... well, actually you might need it just because you didn´t take anything more useful.
If it has eyes, you can blind it, if it has blood, you can make it bleed, if it has a mouth, you can make it scream.
[ QUOTE ]
Don't waste too many slots on Psychic Scream - it's damage is [censored].
Fully slot Wormhole earlier, especially with RECS and ACCS.
[/ QUOTE ]
Talking about waste: don't waste that much time on the boards and get your [censored] in gear in game: us villains miss you! 
I have been told that dominators own at late lvls by many and I am an offensive type so I have decided I want to role a dom (and use double xp weekend to lvl him up) I am stuck between two builds so can I have soem criticism about which one to pick please?
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Exported from Ver: 1.7.6.0 of the CoH_CoV Character Builder - (http://sherksilver.coldfront.net/index.php)
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Name:
Level: 50
Archetype: Dominator
Primary: Gravity Control
Secondary: Psionic Assault
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01) --> Lift==> Empty(1)
01) --> Psionic Dart==> Empty(1)
02) --> Mind Probe==> Empty(2)
04) --> Gravity Distortion==> Empty(4)
06) --> Combat Jumping==> Empty(6)
08) --> Hurdle==> Empty(8)
10) --> Aid Other==> Empty(10)
12) --> Hasten==> Empty(12)
14) --> Super Jump==> Empty(14)
16) --> Psychic Scream==> Empty(16)
18) --> Gravity Distortion Field==> Empty(18)
20) --> Drain Psyche==> Empty(20)
22) --> Health==> Empty(22)
24) --> Stamina==> Empty(24)
26) --> Wormhole==> Empty(26)
28) --> Aid Self==> Empty(28)
30) --> Acrobatics==> Empty(30)
32) --> Singularity==> Empty(32)
35) --> Psionic Lance==> Empty(35)
38) --> Psychic Shockwave==> Empty(38)
41) --> Power Sink==> Empty(41)
44) --> Charged Armor==> Empty(44)
47) --> Summon Guardian==> Empty(47)
49) --> Super Speed==> Empty(49)
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01) --> Sprint==> Empty(1)
01) --> Brawl==> Empty(1)
01) --> Domination==> Empty(1)
02) --> Rest==> Empty(2)
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Or this one?
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Exported from Ver: 1.7.6.0 of the CoH_CoV Character Builder - (http://sherksilver.coldfront.net/index.php)
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Name:
Level: 50
Archetype: Dominator
Primary: Fire Control
Secondary: Icy Assault
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01) --> Char==> Empty(1)
01) --> Ice Bolt==> Empty(1)
02) --> Ice Sword==> Empty(2)
04) --> Ice Sword Circle==> Empty(4)
06) --> Combat Jumping==> Empty(6)
08) --> Hurdle==> Empty(8)
10) --> Ice Blast==> Empty(10)
12) --> Flashfire==> Empty(12)
14) --> Super Jump==> Empty(14)
16) --> Power Boost==> Empty(16)
18) --> Cinders==> Empty(18)
20) --> Health==> Empty(20)
22) --> Stamina==> Empty(22)
24) --> Aid Other==> Empty(24)
26) --> Bonfire==> Empty(26)
28) --> Aid Self==> Empty(28)
30) --> Chilling Embrace==> Empty(30)
32) --> Fire Imps==> Empty(32)
35) --> Greater Ice Sword==> Empty(35)
38) --> Bitter Ice Blast==> Empty(38)
41) --> Power Sink==> Empty(41)
44) --> Charged Armor==> Empty(44)
47) --> Summon Guardian==> Empty(47)
49) --> Hasten==> Empty(49)
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01) --> Sprint==> Empty(1)
01) --> Brawl==> Empty(1)
01) --> Domination==> Empty(1)
02) --> Rest==> Empty(2)
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I know that people will say "why pick a patron pet!?" as many have already. But having more than 1 pets by lvl 47 AND having all that attack and control power will be fun.
So, which one and why?