Favorite DBMS?

No conversations in this tribe yet, so I thought I'd start one. While some may not consider it a DBMS, I've made quite a bit of money developing Access databases for several companies. I worked for 2 years as a MS-SQL DBA for a rather large enterprise organization. I've also developed several web applications using MySQL. Currently I've been playing with Neo4j and really enjoy it's fresh approach. Over the years, I've also touched Nutshell, PostGreSQL, DB2, Hadoop, SQLite, and MariaDB.

While I might say I'm most proficient with SQL and Access, I've been growing rather fond of Neo4j.