The length of this post kinda got away from me, but hopefully some of it's helpful!
As everyone else said, if you want to increase team DPS then support is really the way to go. Kinetics is the absolute king of damage buffing in regular conent, but relies on big mobs to Fulcrum Shift off of and falls off a bit when squaring up against big single targets like isolated AVs or GMs. Debuff-heavy sets like Rad fare much better against AVs, and some buffs like Nature’s Overgrowth can provide hefty damage buffs without requiring big groups of enemies to maintain.
As for personal raw DPS, here’s what I know either from personal experience or hearing from others.
• Titan Weapons is an absolute monster when IOed out. TW Brute or Scrapper with /Bio Armor or /Fire Armor is gonna put out some ridiculous numbers, both Single Target and AoE. Of the two, Bio is more adaptive and survivable, but doesn’t have the raw damage of Burn. Brutes are gonna get more mileage out of /FA than Scrappers just because they have the aggro control to keep mobs from running out of Burn.
• Ice/Fire on Blasters is absolutely ludicrous with the amount of damage (both ST and AoE) that it can put out. It’s obviously less survivable, but can still be built pretty sturdy. If you want pure damage potential and like to live a little more dangerously, this is probably very top of the list (or at least pretty close to it). It can leverage Burn surprisingly well given the slows it has available in Ice, though not as well as a Brute.
• I also remember hearing that Defenders could rival Blaster DPS if they have Kinetics or run Soul Drain (I think available in Ghost Widow’s patron pool). I haven’t tried running Soul Drain on a Defender yet, but I imagine that it combined with a primary that has resistance debuffs and damaging blast set (probably Ice or Fire) could output some serious personal DPS while also bringing nice stuff for a team.
•Heard good things about certain Controller combos (Ill/Rad, Fire/Kin, etc), but don't know enough about them to say much. My understanding is that they bring good personal DPS and control (dispersing aggro for Illusion and more traditional control for Fire) at the expense of weaker buffs/debuffs than Defenders.
• If we’re talking pure single target DPS, both Kinetic Melee and Street Justice for Stalkers can put out some bonkers numbers, probably doubly so if paired with /Bio. These sets aren’t that great on other ATs, but they play exceptionally well on Stalkers. I’m gonna talk a lil more about why that is, because they’re fun and I love Stalkers.
○ Normally Kin Melee gets Power Siphon instead of Build Up, which lets your attacks stack up some +Damage and +ToHit on each hit rather than getting it all at once. Critting with its Tier 9 Power, Concentrated Strike, also instantly recharges Power Siphon (making it pretty lackluster on ATs that can’t crit, like Brutes and Tanks). However, Stalkers get regular old Build Up, can crit on-demand to instantly recharge Build Up (especially with the Chance to Hide ATO proc), AND have an additional chance to recharge Build Up via their other ATO proc. What this means is that Kin Melee stalkers can have an absurd uptime on Build Up, instantly recharging it very regularly and skyrocketing their DPS. It has a very high potential and average DPS, but is a little inconsistent since it has some reliance on RNG. Also worth noting, the cast time for non-stealthed Assassin’s Strike is extremely fast, bordering on instant – most AS are pretty fast out of stealth, but KM’s seems exceptionally so.
○ Street Justice’s combo system works really, really well alongside building up Assassin’s Focus stacks, and Assassin’s Strike builds two combo levels all by itself. Again the Chance to Hide proc is the real star of the show here, since once you build up adequate Assassin’s Focus stacks you can go Shin Breaker -> Assassin’s Strike to immediately be at Combo Level 3, and if your chance to Hide proc goes off you’re guaranteed a Critical level 3 Crushing Uppercut. The extra damage from the combo level doesn’t get doubled by the crit, but it’s still enough damage to almost be on-par with a second Assassin’s Strike. With enough recharge you can get an attack chain along the lines of: (after building enough Focus stacks) Crit Assassin’s Strike -> Combo 3 Crushing Uppercut (Crit if Hide proc went off) -> Sweeping Cross -> Shin Breaker -> Crit Assassin’s Strike -> Combo 3 Crushing Uppercut (possible Crit), etc etc., throwing in the occasional Heavy Blow when you need to build another Assassin’s Focus stack. Both Sweeping Cross and Shin Breaker take -Res procs as well (Achilles’ Heel in Shin Breaker, Fury of the Gladiator in Sweeping Cross), which is icing on the cake and means pretty much every part of your chain either has massive damage with a high crit chance or has a chance to lower your target's resistance. I’ve heard that Water Spout from Mako’s pool can make a nice addition as well, since it can also take -Res procs.
Stalkers feel especially good deleting the hardier targets in mobs while more AoE-focused team members clear out everything else. They don’t bring the team DPS of support ATs, but are exceptionally good at leveraging other people’s buffs/debuffs to put the hurt on big tough targets like Bosses, EBs, AVs, and GMs.
Long story short: Defenders/Controllers/Corruptors bring more team synergy, TW/Bio or TW/FA Brutes/Scrappers deal high AoE and ST damage with decent personal survivability, Ice/Fire Blasters deal obscene AoE damage with lower survivability, and Stalkers don’t have much AoE but their ATO procs can turn them into single-target monsters. It really depends on what content you plan to run, how much you plan on teaming, and what playstyles appeal to you.