Um dunno i think it's kinda hard to compare it to either of these shows but more smallville i guess?

But I think Reaper is starting to look alot like it.

smallville coz jensen was in smallville before supernatural but either than that i don't comapre it to any. I compare Heroes to smallvile sometimes though

I has a lot of things in common with "X Files", the topics, the creatures.. I don't know... And quoting the boys:

Dean: What do you think, Scully; want to check it out?
Sam: I’m not Scully; you’re Scully.
Dean: No, I’m Mulder. You’re a red-headed woman.

Lol!

I think it gets comparied to smallville becuase they air right after eachother, and (at least for me) people started watching supernatural b/c it was on after smallville, I like to call thrusday CW's geek night b/c thoes two shows are different than all the rest of the stuff they put out.

I myself compare it most to Charmed like, Bloody Mary, Wendigo, ...

they've both come in both shows.

but I guess people compare it most to Smallville

I'm thinking of all the times they mentioned X-Files on the show. The sad part is, I've never seen X-Files to get the jokes.