So I am almost finished watching all of The Original Series right now. I've already seen the original Motion Picture, Wrath of Khan, and Search for Spock. I'm just wondering what any other Star Trek fans think I should watch next. I figured I should probably watch the fourth, fifth, and sixth movies next, but what should I start after that? Do I go straight into the Next Generation or do I watch Star Trek Generations as sort of a segue into that? After that, in which order should I watch the rest of everything? Or am I over-thinking it?

EDIT: And do I REALLY need to watch Deep Space Nine?