Best:
Super Mario World/All-Stars
DKC
Killer Instinct
Mortal Kombat 1-3/Ultimate MK3
WWF Royal Rumble, RAW, WM Arcade, Super WM, Smackdown 1, WM2000. No Mercy
Batman: Arkham Asylum, Arkham City, Arkham Origins
Spiderman: The Game
The Suffering/The Suffering: Ties That Bind
Maximum Carnage
Mega Man X
Turtles In Time

More to come later. I'll post worst ones if any come to mind.

Gears of War 2 "I have a rendezvous with death" trailer was absolutely amazing imo.

The Mass Effect trilogy had great trailers from which the launch trailer of the second part I like the most.

Marvel Vs Capcom 3

Street Fighter IV

Not sure if commercials count, but I always thought the Japanese Mario Kart 64 commercial (https://www.youtube.com/watch?v=sHpj0XWXezY) was pretty cool.

This is the best worst trailer. It has nothing to do with the gameplay, but it's very entertaining.

Street Fighter X Tekken - CG Trailer - YouTube (https://www.youtube.com/watch?v=1QoqP0-dCaM)

ive yet to see a trailer (non-gameplay trailer, including teasers) that i can call even bad, much less worst.
what a strange topic

Best (hybrid GP/Cutscene) Trailer: Lightning Returns: Final Fantasy XIII (Yea I know this is Final Fantasy related, but what the heck...and I've seen quite a bit of trailers [as they get released] for this game)
Agni's Philosophy (Final Fantasy XV?)

Haven't seen any trailers I can classify as worst.

best i can remember: dead island,resident evil ORC,Ace Combat 6 Fires Of Liberation...

Agni's Philosophy (Final Fantasy XV?)

Haven't seen any trailers I can classify as worst.

I hate to say it, but this (http://www.youtube.com/watch?v=h542YbZuwkQ) trumps all over Agni's Philosophy (which just came across as mechanical, artificial and just doesn't seem to be Final Fantasy at all) - A New Beginning on the other hand, is epic FF. ;)

But yeah, I haven't really seen any trailers I dislike inherently, if I'm not interested in a game, I usually ignore and forget about it's trailer.