Wow, quite the thread bump. Ok, I'll bite:
Drek: Just used the suck cannon. He kept spitting out mines so I didn't have to waste ammo. Plus, the blaster came in handy.
Thug-bot on Sneevilak: Forgot the turrets, just use your upgraded Heavy Bouncer and Meteor Gun and he'll be dead in no time!
Dr. Nefarious: Same thing: it's just a matter of having powerful weapons, which probably makes the boss level so fun and great.
No hard bosses in DL
SM: Luck.
SAC: Button mashin'
TOD: Tachyon is the 2nd hardest villain to beat for me, so I used the groovitron and Death springs in addition to the RYNO 4 and the Alpha Disruptor. Same with Slag and the Kerchu.
No hard bosses in QFB.
ACIT: When in doubt, spam buzz blades.
A4O: Without a RYNO 6 protosuit, defeating the final boss is hard, but possible.
FFA: Not even gonna…
ITN: Neftin was the only hard (and somewhat fun) boss to kill. A couple vortex grenades will kill him instantly.
Ps4: Snagglebeast: not very hard, just remember to strafe often, and shoot him while he's exposed on the ceiling. The blarg frogs won't attack, because they're slow.
"So we fix our eyes not on what is seen, but on what is unseen, since what is seen is temporary, but what is unseen is eternal."