RE: Super paper mario
Yes, I beat the Pit of 100 Trials. Bonetail couldn't step to my skills.
For the first 60 floors or so it was nothing but Multibounce and I win. Then I had to start trying because I couldn't kill them in one hit... and then they started doing big damage to me due to all the -Defense badges I stuffed on Mario.
For the last ten floors, I almost fainted when I ran into the 2 Dark Koopatrol + 2 Amazy Dayzee team. They weren't too hard, either; Spring Jump, Rally Wink, Spring Jump, 70 EXP for me.
For the fight against Bonetail (as well as the last few floors), I put all the +Defense badges on my partner, and the +Attack badges on Mario and let him clean house. I actually forgot to prepare myself for Bonetail and was worried I'd die and have to start over; I suffered the same fate against the game's end boss. A little preparation the second time around and the boss died no sweat.
I'm playing through it again, but I'm putting all my level up stats in nothing but BP. I completely forgot about the HP Plus and FP Plus badges until I actually found one - I thought I would be stuck with 5 FP the entire game!
The Return Postage badge is entirely worthless unless you beat the Pit of 100 Trials before you beat the game. You can always sell it, but by the time you're able to beat the Pit, money shouldn't be a problem anyway...