Where to start...
As of right now the only MH game I own is Monster Hunter Tri (got it after servers shut down, of course...), and I've beaten it twice as of so far...that mission with the Lagi at the start is what gets me every time.
Pretty much the only monster in the game I have real trouble with is the Uragaan. Everything else poses a challenge once in a blue moon, but other than that, easy. Things I'm good at fighting are: Gigginox, Gobul, Qurupeco, Rathian, and of course those pushovers named Great Jaggi and Great Baggi.
Hopefully I'll have Ultimate along with a 3DS come Christmas, though.
Why must the Wii-U be so expensive?!