Which ipod should I buy?

Well I was thinking about getting a ipod for myself, I already have a android cell so do u guys think I need an ipod,i mean is it worth getting,I already have a 7.2megapIxel camera so I don't basically need the camera faction.i am gonna use it for songs.i want it for school, doing maths homework and for other work.or is it overrated andi should get amp3 player with more functions and cheaper.i was thinking of getting a shuffle cause my budget is $100 dollars but I heard its really random and is just overrated cause of the brands name,i also heard u have to work really hard with cause of no screen.which one should I get?or should I just get a used nano for the same price but I heard used ones have some problems??? or should I just get a persian cat for hundred dollars lol I know its out of the topic but am considering it....cat or ipod or mp3 player???i heard some ipod models have games, do they and are they any good,i heard there graphics are as good as a nintendo ds???