Currently you can try pe2k.com or pldh.net. Most of the BW2 ones aren't different from BW1. We'll have animated sprites on PokemonDb sometime this week too :D
Also, you can just load the Pokecheck image you want instead of the whole page. Copy this URL and change it for the Pokemon number you want:
http://sprites.pokecheck.org/i/494.gif
Different forms have a dash and the form name after, eg:
http://sprites.pokecheck.org/i/646-black.gif