Depends on what you are looking for. Many people consider Wizardry 8 to be the best old school style rpg that has been out in a long time. Are you familiar at all with the Wizardry series? If you've played 7 and enjoyed it, then I can easily recommend this. If you seek state of the art graphics, then I would recommend you look elsewhere. The best thing to do would be to download the demo and decide for yourself. Personally, I like it a lot, and mean to get back to it, although I've been distracted of late. Don't know anything about Ultima Online.
Go to the downloads section under www.wizardry8.com and you should be able to find a link to the demo.
I can't speak to the Ultima Online game but I just finished Wiz 8 a couple of week's ago and really enjoyed it. It is definitely an old school RPG but still fun. A word of warning though, at the start the big battles can be very time consuming and require a fair amount of strategy (depending on your character mix). Once your charcter's reach high levels it is not so daunting. You are pretty much stuck with your main characters for the final levels, so consider that when you set up your initial party.