Ok I'm a huge Buffy fan and I've noticed most of these similarities myself. I love that two of my most favourite characters, while on the surface are very different, are actually quite similar.
CW Sources made a poll where you must vote for your favorite CW bad boy. Damon Salvator from the Vampire Diaries is beating Dean right now! Like whaaat? Lets hunt that b*tch down ;)
If you're interested in supernatural and want to roleplay, SIGN UP! There are tons of characters free right now but they might not be pretty soon so hurry :)
A bunch of fans recording or taking pictures of the exact places the show was filmed(sometimes even the exact time they were filming a scene).It's quite interesting,check it out!