I thought the final boss was cake. I died once because a tentacle pushed me off of the cliff, but that was a fluke. Just hide behind the columns when the beams fire and keep moving when they are not.
I judge the fight difficulty by how many times I died, and the toughest one for me was final round in the second circle of death. I finally gave up when I tried it at level 32, came back at 36 and destroyed everything pretty handily. The Taylortown guy was also very tough for me. You can take out the rocket turret from the top of the building you’re next to, but Taylor himself has a rocket launcher that can kill you very fast. Another tough one was the three Crimson Lance guys, but that was mainly because I kept trying to use the energy cannon, a weapon that’s really only useful for killing Lance Defenders because they can’t block it with their shield. When I switched back to my assault rifle, I got through it pretty easily with chained headshots.
Some of the fights are disproportionately difficult compared to their placement in the game. I though the Nine-Toes fight was much tougher than it should have been, even though I didn’t die with Roland. Nine-Toes himself isn’t bad, but his skag dogs can be brutal. Mad Mel was another tough one. I cleared it with two characters, and died once both times, which allowed me cheese it by parking with the front wheels just over the jump lip and opening up. The second time I played it I even pushed a backup car into the arena before jumping in, but it still wasn’t enough.
The Safe House psycho was tough to kill, but you could run in circles forever and not die, so it wasn’t too bad. Sledge was pretty easy because there’s enough cover and obstacles to kite him after killing everything else. The Rakk Hive was a total joke, and Krom was easy too. Digging machine guy is more long than tough, you have to kill like 10 waves before taking him out. Since after that you can hide and run as long as you want, he’s not too bad.
…at least until my geek friend in the city gets a 360 and I start a second playthrough with him… thinking Mordecai revolver/bird next time…
Mordecai is all about the Sniper rifle. A secondary pistol is cool, and he does have some pistol abilities, but don’t limit yourself to the revolver. I’ve tried both, and really prefer a 12-speed+ repeater for chained headshots unless I have a really kickass elemental revolver. YMMV, but six rounds, or sometimes even just two, doesn’t really cut it against charging psychos. The shotgun, I’ve found, is actually the premiere anti-psycho weapon.