Although I've looked at Dr McNinja for only a couple of minutes, I can tell it's going to become a longtime favorite. I never get tired of Ninjas, let alone Ninjas that are also doctors.
This comic has a great sense of humour, and is also very well drawn. Apparently Dr. McNinja first made his appearance on Something Awful, which might explain a few things. Check this out even if you're not normally a fan of webcomics, this is something awesome.
Link (via 4 Color Rebellion)