A couple things, there are different styles of Jazz and though you may find you like some in each category, you may prefer one style over another.
There are some that may try and make you feel guilty for liking Diana Krall, I too enjoy her music and that is what matters; if you enjoy the CD of hers that you own, buy others and enjoy.
On the same token, there are 'Jazz police' that may want to 'arrest' you if you like Smooth Jazz, again, if you like it buy it and enjoy. I too own the acclaimed Kind Of Blue CD and I don't enjoy it either.
Some others to look into, Eva Cassidy, Chris Botti, FourPlay, Larry Carlson.
Goto to
http://www.bmgmusic.com and search for those you have interest in, if they carry those titles you can play short clips. (Some others on here may know better sources for sampling.) My local Barnes and Noble allows you to play segments of tracks of CD's you are interested in purchasing.