I don't really read comic strips online, but my favourite comic strip is Madam & Eve:
http://www.madamandeve.co.za/It's a very, VERY South African strip, and I'm sure a lot of the jokes are lost on non-S.Africans, but I find it so cute.
The strip has been going for more than ten years, and any political or newsworthy things make it in. It also doesn't hurt that my brother used to work for the company that publishes the strip (Rapid Phase) and so he knows both the artists. My copies of the first three or four collections are all autographed; ain't that cool!
In a strange twist, one of the guys was married to the daughter of my mom's one friend, so the one character in it is named after her!
Everyone in the country totally loves it.
An aside: When I read the subject line, I was like, "My favourite comic? That's easy: Batman!"

Batman really IS my favourite comic book and I buy Batman graphic novels but of course the only Batman movie I have is
Batman Begins because it's the only one that's TRUE to the comic book.