I recently acquired
Torchlight. If you don't know what Torchlight is, the
wikipedia page or the
FAQ may help out.
Initial Impressions: This game is VERY similar to Diablo 2. It's not just the way the game plays, or the skill system, but even the music is similar. Essentially, if you took Diablo 2, changed to look of it (to be much cooler, in my opinion), added a dash of steampunk and threw it in a mining town, you'd have Torchlight.
I've started and played through the first few levels of each of the classes, and, oddly enough, the Vanquisher is by far my favorite. I wasn't sure that I'd enjoy it when I started, but even I can not resist the clarion call of "killing zombies with a shotgun".
The Destroyer is pretty neat, not unlike D2's barbarian, and the Alchemist puts out a good deal of damage, similar to a D2 Sorcerer/Necromancer. Although some will balk at the small number of classes, each one has three skill trees, and each skill tree plays in a VASTLY different way. I've been using mostly the ranged skill tree on my Vanquisher, but the second one is all melee rogue-styled things, and the third focuses on traps like a D2 assassin. The Alchemist has a battle-mage tree, which pumps up his physical ability. It's very varied, and, unlike almost all of D2, they Don't Suck. This is very important. The skill trees actually look like some thought was put into them.
The main thing I want to talk about is the look of the game. I'm not terribly far down into it, but the visuals are STUNNING. You start out in caves, and there are numerous locations where you can see deeper into the cave, and little ratmen are busily mining away, completely ignoring the fact that I am slaughtering their brethren en masse but one floor above them.
While I'm speaking of the enemies... there's a very nice distinction between regular and named/special monsters now. Regulars are of a decent size. Named/Specials are HUGE. If the main character is supposed to be, say, roughly 5'6", I've fought monsters that easily top 20' tall.
The way weaponry works has changed, at least as far as I can tell. Critical hits and Glancing Blows can happen, the former usually leading to splattered enemies and the latter usually leading to "oh fuck, I need better weapons NOW." Right now, I have an electrically-charged rifle, and when that thing crits, the attack explodes in a ball of electricity. It is just awesome to look at.
Another new feature is the Pet. You can have either a dog or a cat, and can also name it. The pet counts as an extra attacker, a meatshield, and extra inventory space for all sorts of things. Pets can also be equipped with two rings and an amulet, which allows a further degree of pet customization. Also, if you go fishing, you can feed the fish to your pet for various results... including things like "drastically increased magic item or gold finding for x time" or "turn your pet into a fire elemental for x time", things like that. It's pretty awesome, and makes fishing actually worthwhile. To make the pet even BETTER, you can load up its inventory, send it to the surface, and it'll sell everything and come back with cold hard cash.
There's a few other things I'm going to kinda either rapid-fire through or miss entirely.
There's a "Fame" score, which goes up by doing quests and killing rares and whatnot. When you Level up your Fame score, you get a free skill point to spend. There's a guy who transmutes shit for you, so fuck the horadric cube. There are two guys (I think they're orcs or goblins) near the edge of camp, one will destroy items and recover gems, the other will destroy gems and give you back the socketed item. Picking up gold is crazy easy now, just run over it. Shift-clicking an item will have your pet pick it up. The old "armor changes the look of the character model" is back, and upgraded, too.
So, tl;dr: if you liked Diablo 2, give Torchlight a try. I doubt you will be disappointed.