Both films were good, but not great. I thought the animation style in Atlantis generally looked nice, I liked the use of blue light and the design of the writing and symbols. But the main characters sometimes looked to angular and awkward for my tastes, whilst the whole thing sometimes felt too Saturday-morning cartoony. The plot was rather simple too, and there was at least one plot hole in there - for example, if the crystal feels in danger why take a host? How does that help the crystal protect itself?
The main attraction of Atlantis though was the voice cast. It had Michael J. Fox voicing the main character, Leonard Nimoy as the king of Atlantis and John Mahoney, who played Martin Crane in Fraiser, as the old rich man funding the expedition. However it doesn't quite match the Disney classics like The Lion King, and now I think of it, Atlantis didn't contain any songs.
The Time Traveller's Wife, starring Rachel McAdams and Eric Bana, was better, though it would have helped if I'd seen it from the beginning. It had believable performances in it, good affects and was generally a good weepy film that tugged on your heart-strings. However, there were one or two plot holes in it.
Anyway, those are just my opinions. Check out the trailers, and perhaps even check out the films, and tell me what you think!