I have begun to experiment with FileMakerPro http://www.filemakerpro.com/ just because.

I hit a lot of Oracle servers that are running behind many of the production systems here (mostly large scale datawarehouses and a problem management server).

I have hit but go rid of Informix which was running behind our cal center switches.

I have hit SYBASE but no longer which was a problem management server.

We are playing with MySQL a bit here (just because someone said let's take a look).

Use Access (many legacy user databases I am still resposible to support version 2, 95, 97, and 2000).

There are just so many out there thou that it makes for quite and interesting time if you explore them.