I've played through Titan Quest recently, had started it a few years ago but never got around to finishing it. Recently a friend of mine (same friend from RE5) had expressed interest in beating it, so we started new characters and beat the game. Now we're on the expansion though, which is surprisingly long for 1 act in the game. It's almost as long as the entire game :P but I'm not complaining, it's very entertaining and fun.
My character is a ranger (Archery and Nature masteries) although I've only used the healing spell and Heart of the Oak for nature mastery, the rest of my points have been going in archery. My friend, on the other hand, decided to me a mage (thank god, didn't have to argue about who gets what drops) and he went with the earth and storm masteries.
The start of the game was a bit slow, but it really catches on later. We've only beat the game once, but there are different difficulties to play the game on once you've beaten it a few times. We will probably keep playing after we're done with it this time, so we can experience having our characters maxed out.
After getting by the starting area, it gets a lot more interesting, because you meet up with some people that you might actually recognize in real life (for example; Leonidas and a few others later on)
Another great aspect of the game is mod support. There's a game mode called "Custom Quest" on the main menu which allows you to select user made Quests to try. I've downloaded a mod myself called "Titan Quest Lilith TWoD Battles of Jalavia". Here's a video of me demonstrating a few of it's aspects.
As you can see, it changes a lot of the game's structure (as in mastery selection and shop items. You can even stack 25 potions on top of each other as opposed to the game's regular amount of 5)
The only problem I have with the mod is that you can't hear people expressing their dialogue, but I didn't really expect to see that in a mod anyway.