I like his post-Beatles solo work the most of any of the Beatles, easily. Photograph, You’re 16, and The No-No Song come to mind immediately.
And I have to give him a WTF Award for his video of “Only You” (with John Lennon):
http://www.youtube.com/watch?v=53C8hVR_YuU (starts about 15 seconds in)
Some of his early solo work was written or cowritten with George Harrison. He was also smart to get very good musicians and producers. I don't care for the Beattles that much, but I do like Ringo and have his songs on my playlist.