Well I think it is kind of funny we're ranking trailers now, but anyway I have yet to see the Shrek 3 trailer, so take that into account.
Most of the movies I am at least mildly looking forward to. With that said Harry Potter had a lame trailer unfortunately, Ghost Rider was a little too generic with all the superhero movies out these days and I thought Transformers looked like War of the Worlds except with more focus on the giant robots than the WOTW promotions.
That leaves what were 3 very good trailers. FF2, Spidey 3 and 300. This is all about preference. Albeit, the Fantastic Four trailer showed no real depth of story and was just a showcase of SFX. But it is a teaser so I'll cut it some slack, but besides proving the action will be better, I am still not convinced the quality of story, characters and plotline will be better yet.
I think 300 was a great trailer, but I a mmore hyped for Spidey 3. It promises amazing action on level or better (and most like.y better) than the groundbreaking work in the second movie and the hint of **** hitting the fan between Pete and MJ, as well as character pay-off for Harry and just cool visuals like Peter literally tearing himself apart to get the symbiote off got me totally hyped (as before I was relatively low on hype). And we haven't even seen Venom yet (officially).
But I could see 300 and FF2 getting just as many votes, it is really preference as those were all pretty damn good trailers. Alas, summer is far though.