well, there are a lot of differences.
i suppose the main one would be file and folder permissions. ntfs allows you to use much more powerful settings insofar as access by users and groups, whereas fat32 is tailored more toward performance, ie. access time, etc., but allows for less flexibility for permissions. some would argue that ntfs is less prone to fragmentation, but i think the differences in that respect are overblown.
i use ntfs, not because i need to, more just to learn by using.
there are other differences, which i will not go into because they are covered EXTENSIVELY by documentation (see the microsoft knowledgebase), but suffice it to say, i don't think using one or the other will make a huge difference to the average user, unless you are on a domain or are concerned about security and/or privacy.