Your GoTo sets...

This is a lot harder than listing sets I hate, but if I have to pick a top 3 sets they would definitely be:

Fire Blast: So far above every other Ranged damage set for Blasters and Corruptors that it's laughable, although Defenders can get more mileage with a good debuffing set like Sonic Blast. I can't play any other Blasters since I already have a Fire-Fire... anything else is a step backwards for me.

Dark Miasma: This set is so overpowered it hurts. It herds, it tanks, it has amazing heals and regen debuffs, it controls, and it has one of the special toggles that I call the trinity of uber toggles: Shadow Fall, Arctic Fog, and Steamy Mist all give a heaping amount of resistance to more dangerous types as well as solid defense, and protection to one of the more lethal and less widely resisted Mezs (confuse or fear depending on the toggle).

Fiery Aura: This set isn't the king of farming for nothing. I remember farming with a purple'd out Fire-Fire Tank in the issue that purple sets debuted, and dealing with Burn's fear and taking it in stride, before the AMAZING BUFFS that befell Fiery Aura and eliminated all it's weaknesses turn it into the overplayed set that it is today.

I try to have one of every set, so that leads to few repeats. That said, I have unintentionally made 4 dark armor, and 4 willpower characters, and my 4 radiation emission characters. Whoops!

Dark Miasma for me too please, it's just so awesome.

That said, I have tons of alts but not a lot of toons who've gotten past 30 or so. Thinking over them, I can't say I really have any repeats except for SR, one a stalker and a scrapper. I've enjoyed each and every set I get that far and probably feel some sort of rerun burn-out on the others which keeps them from grabbing me so much that I get them past 30. But I do still like them.

I've found it hard to use any other melee set beyond Claws these days. I really wanted to get into Titan Weapons and tanking too, but its just too fun being the Ronco Villain/Hero-O-Matic.

I was going to say that Grav is my GoTo for Control and nothing else. Then I had a look over my characters...

Control - Gravity (x7)
Melee - Claws (x5)
Armour - Electricity (x5)
Blast - Radiation (x4)
Support - Force Field (x5) & Time (x5)

Grav FTW! Interestingly (to me at least), although I have a Grav/FF, Grav/Time and FF/Rad, I don't have a Claws/Elec... this must be remidied!

Energy Blast/Manipulation
Kheldian's FTW!

Other than my DP/Fire blaster (which i'm not feeling now-a-days) I haven't loved a powerset enough to get it to level 50. Although, my Katana/Super Reflexes is catching up pretty quick.

Defense sets: Shield & Invulnerability
AAO and Shield charge are too much fun to pass up. Invulnerability when slotted up with sets produces a powerful reliable layered mitigation without any real drawbacks, except that Psi hole. Then again what defense set doesn't have a psi hole?

Blast sets: Archery, Sonic Blast, and Fire Blast
To me ranged attacks are all about leaving everything in range twitching on the floor and then doing it again. That is why archery and fire blast are go to's for me to get everything defeated fast. Sonic is a different type of fun for me. When the team or league I am with has hard targets to take down my sonic characters shine.

Melee sets: Fire melee and Broadsword
Fire melee's strong mix of single target and AOE damage combines with so many sets that I just have to talk myself out of fire melee when creating new toons.

I know Broadsword is a bit long in the tooth and seemingly overshadowed by titan weapons but you still can't argue with catching a few foes in headsplitter, and thwak, watching bodies hit the floor.

buff / debuff sets: Radiation Emission and Sonic Resonance
OK' I have a problem when it comes to rad. I like dead team mates. Using fallout, vengeance, and mutation I can turn an encounter that is headed south around real quick. combine in the multi-level debuff toggles and a Rad can pull a mob's teeth before the fight starts.

Sonic Resonance didn't really do much for me till Apex TF came out. I pulled my sonic / sonic defender out for Apex to give her one last chance before deleting her. I threw together a cardiac T1 out of spare shards and components to join. This team got MoATF first time through because my sonic buffs took the edge off and the sonic debuffs made short work of Battle Maiden. When I bring this toon out in leagues, if I wait long enough, someone will be convinced to roll a sonic resonance or someone will exclaim about the speed by which the AV was defeated.

Traps and Shield are both sets that I have an unhealthy relationship with. I have also made several Robotics, Dark Miasma, Fire Blast, and Sonic Attacks characters. Ninjitsu should probably be on this list too as I've never been able to bring myself to make a Stalker that wasn't /Nin.

I24 Proc Chance = (Enhanced Recharge + Activation Time) * (Current PPM * 1.25) / 60*(1 + .75*(.15*Radius - 0.011*Radius*(360-Arc)/30))
Single Target Radius = 0. AoE Non-Cone Arc = 360.

Illusion Control, Cold Domination, Dark Melee and Invulnerability.

I try very hard to make my characters varied, so there's not a lot of repetition. There are, however, some sets that I find myself gravitating toward naturally whenever I go to make a new one: Dark Armor, Gravity, Super Strength, Street Justice, Time Manipulation, Fire Blast, Storm Summoning, Electric Armor.

I have a Dark Melee character of every melee AT (and a Dark Manipulation Blaster), at least 5 Shield characters, and 4 Kineticists.

Ninjitsu is the only secondary I run on Stalkers. If I am missing out, oh well.

Dark Assault does not get me excited to continue my dark streak (and I was looking forward to a Dark/Dark/Soul Domi). Perhaps after my Peacebringer it will be time to roll a Warshade.

I have 450 levels worth of Rad/ Defenders and /Rad controllers and corrupters.
I have 200 levels of Mind Control.
I have 150 levels of Kinetics.
I have 150 levels of Plant Control.

Looking at all my 50s (if I can remember them all), these are my most used sets:
5 with Storm Summoning - Storm/Dark, Ice/Storm, Mind/Storm, Storm/Sonic, Necro/Storm
5 with Dark Blast - Storm/Dark, Rad/Dark, Cold/Dark, Dark/Poison, Dark/Nrg
4 with Energy Manipulation - Arch/Nrg, Elec/Nrg, Psy/Nrg, Dark/Nrg
4 with Kinetics - Grav/Kin, Fire/Kin, Ice/Kin, Kin/Sonic
3 with Radiation Emission - Ill/Rad, Rad/Psy, Rad/Dark
3 with Super Strength - Ice/SS, SS/WP, SS/Fire
That's all I can think of to that extent, listing "2 with..." options would just get retarded.