It's a decent game, solid I would say, I rate it a good 6.5/10, but it's not entirely stable, there's many noticeable bugs, but the game world is very, very big, there's around 600 side quests, if not more than that, five difficulty settings (last one being the best, Niobium), superb graphics, decent although not varied music, silly character one-liners but can be funny at times (Seraphim voice over is horrendous, but it somehow makes it funny sometimes, for me anyway). The story is weak, but it unfolds nicely, the main bosses are relatively easy, but the very last one is quite a pain in the back, although the last level itself and the regular mods of that level are much more challenging than the final boss (final boss in plural, you'll understand once you get there, I don't want to spoil too much).
And there's the expansion pack, Ice & Blood, which includes two new areas, a new character, new items and a serious overall buff to enemies (from what I've read), it's released in Europe but isn't yet available in North America, it's supposed to be released here next month. The expansion also supposedly fixes a couple of issues but still has a few ones such as the infamous "black screen with cursor and nothing else" after entering or exiting any indoor area from outdoor, or vice versa, and some others. I myself am playing off-line in single-player, I tried to play on-line and only play on American servers but the ping is horrible (their "American" servers are located in Europe, last I heard, but Europe or not it doesn't seem to make a difference), I always end up either getting disconnected or dying due to lag spikes, but it's not a big deal since the game is pretty much dead on-line, I don't think I ever saw more than a dozen people playing at any given point, so staying off-line is not a big loss, but still a shame.
I played Titan Quest for about two weeks and I uninstalled it, it felt very bland and boring, more so than Sacred 2, but to each their own taste, I just prefer Sacred 2 overall, but as much as I hate saying it the one point that Sacred 2 really shines about really is its graphics, if you play it at maximum settings with the PhysX effects enabled, it's a very beautiful world, superb lightning and shadows effects, the water is barely equaled in any recent games I can think of, the textures quality is something you see occurring very rarely in PC gaming due to multi-platform games, Sacred 2 was ported to the Consoles, rather than being ported from them, and Ascaron really did take advantages of PC hardware, even with my GTX 285, if I play at maximum settings I get regular slow downs in populated areas and especially at night time with the dynamic shadows in cities and towns, but it's really worth it just to look at.
To reiterate, overall Sacred 2 is decent, it's nothing special but it can certainly fulfill that thirst for hack and slash in the meantime until Diablo 2's next patch or until Diablo 3 comes out.