I preordered the game, and had it beaten by around March 12th. Wasn't too happy with my ending, but we don't need to talk about that. I really liked the character loyalty system - as opposed to "loyalty missions" in ME2, in ME3, you just get the chance to participate in a dialogue-based cutscene that is really kind of fun, and brings out the characters a lot more than I saw happen in ME2 - with the notable exception of Jack's ME2 storyline.
The Multiplayer in ME3 is a lot of fun, and it's been eating up a good chunk of my videogaming time - I love how you can use earned money in the game to purchase "booster packs" that unlock new class options, weapons, and weapon modifications. When I unlocked my favourite little Carnifex Pistol last week, I was a very happy Wik. One thing I don't like is that when you gain a level in a class, that level transfers to the other 3 race/gender options for that class. Since classes seem to cap out at level 20, this means that I see limited advancement opportunities in the game - all of my characters are around level 19 now, with the exception of the Infiltrator, a class I absolutely hate to play.
I also hate how buggy the Vanguard is in multiplayer - it's my favourite class, but one I very rarely play because that bug is so annoying. I actually restarted playing ME1 as a Vanguard because the class is so much fun, but I've come to realize that the classes in ME1 are nowhere near as fun as they are in 2 and 3. This is making replaying ME1 something of a chore.
As for ME3, I like most of the game, but I kind of hate how I'll be walking down a hall and some Volus will be like "Damn, I left my keys on the Planet Agaris 7". And then you suddenly have a quest to get back that damn Volus' keys so he can help you in the war effort. At one point, I had about two pages' worth of these stupid little item retrieval quests - that just involve you going to a planet, scanning it for stuff, and then giving the item back to the necessary character. Annoying for a completionist such as myself.
Squad control is the best it's been in the series, though, and unlike an earlier poster, I found myself using different group combinations for different mission types. I also found myself bringing in characters I thought would be interesting depending on the mission at hand - sometimes, this even opened up huge dialogue options between your two squadmates! I love it when that happens.
There is a fun fact that may be a tiny bit of a spoiler, but I think it's one worth sharing: After the credits, there's a tiny cutscene. The main voice in that cutscene is our friend, Buzz Aldrin. The fact that Bioware got Buzz Aldrin to voice a character in a video game is probably one of the coolest things ever.
Oh, and the music in ME3 is the best in the series. The reaper theme music, with piano notes in minor keys interspersed with thundering synth-organ chords is incredibly cool. Every time it came on, I just wanted to pause the game and listen - and did, quite a few times.
