So, most anime are made from manga right? But some sure can vary from paper to animation! Just, list the worst once (trail too far off than the orginal book) and the best (like moving paper!) Mostly made this to see what anime are close to the manga.
Naurto:
I swear, this is the BEST manga to anime I have seen! It's almost EXACT to what I read! The only difference was when they introduced two characters at the begining of the anime that orginally wouldn't be shown until later (Hinata and Sakura's rival).
One Piece:
Some of the episodes are jumbled up, but this one's pretty good!
Rurouni Kenshin:
Some character in the manga that aren't in the anime vice versa, but either than that it's not too bad.
Cardcaptor Sakura:
Actually, this one isn't that bad either. Couple different things, (like fewer cards in the manga) but yeah.
Chobits:
Not too too bad. Some stuff is jumbled up, and the ending is different, but overall not too bad.
Sailor Moon and Tokyo Mew Mew: Whoa! The anime is sure WAY different than the orginal manga! (especially SM!) So much random stuff is added to the anime and all... still not bad shows, but yeah.