Slot everything for knockback and go play PvP. That'd be sure to annoy the hell out of heroes 
IN MEMORIUM OF GAYBABY
CRUELY TAKEN FROM THIS WORLD WHILE SO YOUNG
On paper it looks good, and IMO the best dom for soloing. But thats all on paper, never actually played it
"Well, they found my diary today.
They were appropriately appalled
at the discovery of the eight victims
They're now putting it all together.
Women wrapped in silk
with one leg missing
Eight legs, one body, silk,
spider, brilliant!"
Well i just started one myself not long ago. So far he's pretty fun, lacking holds with mine atm but due to trying to make a rather unusual build or so I'd like to think
I played several grav/ doms in CoV beta and early release (and a grav/ controller in CoH, which I've since deleted) just because I love Propel - it may not be that effective (looooooong animation time) but I think its a 100% guaranteed knockback and surely nothing evokes superpowers as well as throwing cars/forklifts/snooker-tables/computers/tables/anything at your enemies. I love it - so much fun.
I really wish another powerset had a similar power (it could probably fit in Kinetics thematically, or maybe Super Strength's Hurl could have you chucking random items instead of rocks), because sadly I really don't like the look/effectiveness of the rest of the grav/ set. But I still keep wanting to make a grav controller (probably grav/kin) or dominator (grav/energy maybe) just for "Propel goodness" 
I Like my Garv/Energy Dominator so far. Not it does not have the fantastic damage output of a corruptor, but when I can hold 2 of the 4
Minions (+1) in an encounter, and have the last 2 immobilised and still fit in some attacks... well they do not get to do that much damage to be either.
I guess it like with everything else, a matter of taste, but I must say that the knock back and disorientate of energy definitely falls in my taste. And while garv is not the most visual hold/imob it is serenely effective. Still only level 24, but I like it very much so far.
I have one at lvl 9 i think he is (GravenBot) and enjoyed playing him.
I love the holds and although not massive the energy damage isn't too bad.
I have heard alot of complaints about the other Doms but so far this seems the best imo.
Singularity is a high point of this build, in my opinion its the most suitable pet for a Dominator (very tough, great for taking alpha strikes, its slightly lower damage output not a big deal with a Secondary full of attacks).
Having played my first Dominator as my first villain, i got him to lvl 32 and got very bored. I found leveling slow and just didnt do enough damage for my liking.
This put me off dominators until now....
I made a gravety/energy dominator the other day and ive gotta say this was the most fun ive had with a toon in ages. i like the holds and the way u can fling ur enemies all over the place (rag doll makes this look cool and sometimes funny).
Even though my toon is only level 7 he seems to do considerably more damage than my fire/ice dom did. The fact that u can do good damage from both grav and energy sets is a bonus imo especially if solo a lot.
Having lost interest in this AT i have found a new fun life in the Dominator i just hope the later levels are consistant in what i have experienced so far.
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UNION
CoH
Captain Phantom - Lvl 50 energy/elec Blaster
Haruko Chiaki - Lvl 50 MA/Regen Scrapper
Mini Phantom - Lvl 45 ILL/FF Troller
CoV
Devil Phantom - Lvl 40 DM/FA Brute
Evil Iceburn Kid - Lvl 32 Ice/Fire Dominator
Chunder - Lvl 17 EN/EN Brute