How safe is an MD5 hash of a plain password?

First of all, I hope that you've moved beyond MD5 hashes and hashing passwords by themselves, adding salts, etc., but I do recall systems in which an MD5 hash of a password by itself was "good enough".

You can look up some md5 hashes on this md5 cracker page. I found many two word combinations that were crackable.

You can play with generating md5 hashes of questionable passwords (such as your name and p@ssw0rd) with this md5 Hash Generator