Blambot is a good source! I use Blambot's Nightwatcher font :> even if it means pissing off letterers since the font only has crossbar i's... womp womp. But I'm partial to the upper-lowercase font, rather than the traditional all-caps.
You might also try 1001 Free Fonts, but I would be careful as not all of the fonts on that site are ideal for lettering.
The thing about comic sans, aside from it being an internet joke, is that is wasn't even designed for comic lettering to begin with. Aside from looking goofy and generic, it has uneven kerning, which makes for sloppy lettering.
A good rule of thumb when choosing comic fonts-- if it came pre-installed on your computer, don't use it!