The 'clones' that spring to mind:
Baldur's Gate Dark Alliance
...and its Snowblind engine brother from another mother, Champions of Norrath. Good enough loot. Boring skills. Fun but shallow, which makes it feel much longer than it is. Noteworthy for doing console ARPGs right (and for having very sharp visuals, even on PS2). Made entirely obsolete by Diablo 3.
Darkstone
Apes the Diablo formula very closely, but has more outside environments. Bright and lighthearted. Early 3D, so the visuals aged poorly.
Nox
Zany and fast. Requires more dexterity than its cousins. Linear and static, so might not even belong here, but Westwood were gods and this game is good so fuck it. (Want to add Divine Divinity too, but remember even less about it. Similarly linear and static though. I think.)
Throne of Darkness
Samurai-era demonry. You control a squad of samurai rather than just one person, so some tactical wrangling required. Remember it having an odd upgrade and item system and I ultimately didn't get along with it.
Torchlight
Diablo set-up (hole in the ground, explore it), but has pets (to sell loot and buy potions for you) and fishing. I finished it, but it bored me to death. Remember nothing of quests and skill systems. Sequel was more of the same, but more varied environs.
Sacred
Doesn't have much going for it besides its custom combo system. ...Germany represent! (RIP Ascaron)
Soldak Entertainments's output (Depth's of Peril, Din's Curse, Zombasite)
Perhaps the most complex games on the list. Only ever played the demos (and bounced off). The loop matches Diablo closely, but they're more systemic, with less bespoke content, i.e. quests feel or are randomly generated, with dynamic objectives and time limits that actually matter and shit.
There are more recent games like Van Helsing, Victor Vran and Vikings - Wolves of Midgard, but they're in the Dark Alliance and Diablo 3 mold and are all going to be quickly forgotten.