As far as film like look, you might wanna check out Digital Film Tools’ Filter Bundle. It comes with a crapload of 55mm filters, some of them pretty cool and from my experience they are not heavy on rendering time…Unless you are running on a slow machine…As far a popular plugins..I’d say Trapcode Shine is probably the best bang for your buck…If you have money to dishout than Cycore FX HD,Boris Effects,Tinderbox,GenArts release is a good bet…Personally I don’t like TinderBox because you can’t apply a mask to it, you have to precompose…If you are looking for a particle generator look no further than Trapcode Particular. Particle Illusion is a pretty powerfull standalone paricle generation.
For 3d stuff in AE Zawerks 3d Invigorator is a good bet…Even though you are probably better off spending extra 500 bucks and getting a full fledged 3d program…
I hope this helps