SERIOUSLY people STOP recommending Clannad. You're gonna put this guy off anime before he even begins. Clannad is an amazing anime, but it's not an entry level anime. Recommend him stuff that is good for someone who is just starting to watch anime, not ones which are enjoyable for seasoned anime watchers. Plus it's a very slow slice of life/romance anime that you really have to sit through to enjoy since it takes time to build up. Afterstory though, I almost cried at how amazing it gets in the second half.
I would personally recommend Naruto, Attack On Titan, Full Metal Alchemist, Bleach, Death Note as anime to get your feet wet. They will get you used to anime in general. After that it really depends on your taste. There are a LOT of anime and you just have to find the types you like best. Those can be separate recommendations in and of themselves.
I will however recommend two crazy awesome anime. GTO (Great Teacher Onizuka) and Level E. First one is one of the funniest anime ever made and the second one is just a straight up troll anime. It's purpose is to troll the audience.
