Just off the top of my head, pretty much anything goes with anything. But if you're looking for a duo that helps and supports each other, I would suggest a Melee/Support combo. Scrapper/Controller, Tanker/Blaster, Scrapper/Defender... something along those lines.
Melee to draw the initial agro, Support to do whatever that AT does best, to back up the Melee.
But above all, pick two AT's that you can have fun with!
Good luck!
Petey Quick, SL50 Ene/Ene Blapper - Cynapse, SL50 Inv/Ene Tanker
Witchblaze, Fire/Fire Blaster - Lo Ping, MA/Regen Scrapper
Astre, Fire/Kin Controller - Terri Volta, Rad/Rad Defender - Solarkinetic, Peacebringer
Yusaku's Guide to the Energy/Energy BLAPPER
There are a few that have disproportionately bad meshes. That isn't to say it "NEVER" works but it takes a lot more effort and may never approach the average. (Note that there isn't really a generic "Defender" the way there's a generic "Scrapper".)
Storm Defender/Scrapper is substandard, and so is Blaster/Scrapper. Kinetic Defender/Blaster is problematic. Anything where neither character is "the damage" [Defender/Controller, Tank/Controller, whatever] will be kinda slow.
There are other combos that work VERY well. Fire Tank/Darkity-dark-dark Defender is one[ the DD has area-based buffs, an area immobilize, and some Def/Res; the Fire Tank has Burn, which people might otherwise run from.] At the moment, Super Reflexes scrappers and Force Field defenders mesh very well defensively. [FF isn't much help offensively, though.]
The important thing is, play something you're going to be happy with for a long time.
Mini-guides: Force Field Defenders, Blasters, Market Self-Defense, Frankenslotting.
So you think you're a hero, huh.
@Boltcutter in game.
Hi I have been playing CoH for a little while and it just occured to me to post here with this question.
I play mostly with my gf in the game and sometimes with my roommate. What I want to know is what two sets would be good for me and my gf to play together. We want sets that we will be able to play exclusively a lot of the times. Obviously we will group up at times with other people and obviously we will be grouping up for TFs and the such, but we want sets that will work well when we do play by ourselves.