I'm always on the prowl for a possible transition from VFP and ran across the following. Interesting information on their websites and seems to be obvious contenders.
Alpha Five - uses dbf's natively, no runtime fees, potential to develop web apps as well.
Filemaker Pro - seems to be a lot of users and has a native database, free distribution of apps, lots of support.
Realbasic - cross platform, no runtime fees for single user versions.
John Fatte'
Life is beautiful!