I've always loved the second part of Act III, after the jungles. The huge amount of stashes is awesome, and the enemies are damn cool and fun to fight to boot. Definitely one of my favorite areas in a game. I got two Iceblinks back in classic (this armor was a big deal back then, for those of you who don't recall) by opening chests and stashes there.
If I get to a high enough level, I may do Kurast runs and wear fighting gear, kill all the enemies, then switch to MF to open all the chests, stashes, corpses, logs, etc.