Hey i don't know much about formats either but i think that the best looking is .avi but it is also kinda big and takes up space. then you got .wmv (or windows media format).
Then i think DivX is like really good because it is a smaller format.
sorry I don't think i said that right. i meant the DivX makes smaller files. just go Googling i am sure you'll find some formats.
just type in a search for VIDEO FORMATS or whatever you're looking for. just a hint...to me it is hard to find a good looking format that is also small. it seems as if they look good they are always big. to me the Megs and Gigs are no prob but if you can find a format that fits your needs Google is the answer.....

Good Luck-