Health potions I hoard; the rest I mostly sell off. (Since my characters are both warriors with very low int. the mana potions are useless anyway.) Of all the strange places, they're coming in very handy in the Act IV Battlefields, where the NPCS tend to be witches, clerics, and mages, and can throw spells with a hell of a punch. If five or six of those hit you at once, you need the potions to live because you can't strike back for a bit.
In DD I cared more about the potions and about alchemy than I care in BD, but with the way the skill tree works now, I had to unlearn my alchemy skill because I simply needed the points somewhere else. (I loved the way DD skills worked; I miss it.) I haven't found a situation where the temporary skill boost was worth it, although I may hang on to more potions as I go into Act V because you never know what kind of heavy-duty boss-type characters will show up as you head toward the end of a game.
