Easily my 2nd favorite web comic ever is Evil, Inc. It's been around for years, so if you haven't read it, do so as soon as you finish reading this post. Do not past Go. Do not collect 200.00. Unless, you know, someone owes you 200.00. But then go read it. It's full of awesomeness.

Another good one is Amazing Superteam. Poor art but good dialog and decent storyline keeps this comic going. I like it a lot.