In an RPG, I'll complete the game normally, then on my second playthrough, I'll use haxx0rz to boost my level/stats/gearscore to redonkulus levels and absolutely curbstomp everything. On the highest difficulty, if applicable. Also, come hell or high water, I WILL get the ultimate weapon!
... if I know how.
Also, whenever I play a Kingdom Hearts game, I always do this: Defeat the final boss normally, grind to the level cap, then defeat the FB again... with no accessories and the starting Keyblade. It's a lot more fun than it sounds, actually.
EDIT: Also, during previously-mentioned haxx0rz-fuelled rampages, I'll often go for asthetics over effectiveness when it comes to gear. My character in Dragon Quest IX has maximum stats in everything, so the only reason I'd put on endgame-level armor instead of his snazzy vest is due to the armor's secondary ablilities.