Sounds like you're into Western Action-RPGs. The bad news is that you're just about out of the usual candidates (especially if you've already played through Titan Quest and Immortal Throne; and I assume you've already played the omitted sequels and expansions like Diablo 2 & LoD, Dungeon Siege 2 & Broken World, etc). One potential candidate is
FATE which was made by Travis Baldree who'd later move on to (the now-defunct) Flagship Studios to create Mythos (currently in limbo). After that, though, you're basically scraping the bottom of the barrel with games like Silverfall and Legend: Hand of God, etc.
Some good news is that Sacred 2 is supposed to be out this September. Plus the kill-n-loot theme is one of the staples of MMORPGs, so you could always look into that. In other news, Gas Powered Games just released Space Siege... but I wouldn't recommend it since it's sorta a dumbed-down mediocre mess. If you
do want to shoot tons of aliens with some light RPG elements, you're better off just getting Alien Shooter: Vengeance.
Well, either way I guess we're still deviating from the RPG genre. If you start to lean more toward the RPG side I have a few recommendations:
Divine Divinity (2002) -- basically if you took Diablo or Sacred and focused more on the RPG part (one of my favorites, and also has a sequel coming next year). Avoid Beyond Divinity.
Arx Fatalis (2002) -- essentially a spiritual successor to Ultima Underworld.
Gothic II, III (2003, 2006) -- a German action-RPG series, mostly a cult series over here. A bit rough around the edges, but some people just plain adore this series.
Vampire the Masquerade: Bloodlines (2004) -- sequel (although unrelated) to Redemption and another cult favorite RPG set in modern day LA.
The Witcher (2007) -- Probably the best Western RPG of the last few years.
Just note that Bloodlines and Gothic 3 were a mess when they came out. If you're gonna take the plunge, make sure to find their latest respective Unofficial Patches. And I was obligated to mention The Witcher, but it's still a pretty new game and does require a somewhat decent machine to play well. Regardless, the Enhanced Edition of The Witcher is scheduled for September so I'd hold off until that's out anyway.