Deep and expansive, with fantastic graphics, and the best economy of any MMORPG. Patience and maturity are required.
It's a very open game. And skill training and progression take a lot of time. So it's not for people that need direction or lack in patience. It's for mature players, and the people you meet in the game really reflect that. While there are griefers, most don't last long because they usually lack the commitment to make a long term investment into this game.
Combat is excellent, and some of the best MMORPG experiences I have had come in witnessing large-scale fleet battles in eve.
Only drawback is that sometimes the 'grind' is this game is pretty transparent.. and it often feels like another job rather than entertainment. I've taken several long breaks from this game when other offerings become available.. but have come back to it several times when I find myself needing to pass the time.