There are so many ds's and stuff so how do you know which one to buy. You dont want to buy one and know you bought the "bad" one. Well first well talk about the first ds. The first ds could play gameboy games and ds games. the only bad points were that the screen was dark and it was kinda bulky. If you have alot of gameboy and ds games or you like old game systems i would advise this. you could probbably find one of theese on amazon maybe. Next is the DS lite. It's the same thing (as a DS above) exept the screen was brigter it was thinner and it portrayed the symbol of the "double screen" on the top. The bad point was gameboy games had a dark screen. this is basically the advanced version of the origional DS. next is the DSi. The DSi could not play gameboy games but it was even thinner and it had more features such as the dsi browser, flipnote studio, pictures, and more. The DSiXL is the same as a DSi exept bigger and came with a few pre-downloaded apps. the 3ds is the new dsi. you can watch videos, collect pokemon, and more. you can have friends and you can connect to their games over the internet. for example: if you are playing mario kart 7 and you want to race someone else you go to your friends list and you click "join game" and youre connected. if you buy a 3ds dont forget to download some of the free apps on e-shop which is the new dsi shop. you can play all kinds of games off of e-shop. on the photo apo you cannot use as many things as the dsi but you get new ones like sepia, dream, and low-light. you can also take videos in 3d and regular. certain cards come to life with AR cards. place a card down and watch as it comes to life before you. some ar cards that come with the system is toon link, 3 pikmin, mario (of course) and more. tag other 3ds systems in mii plaza and much more. the 3ds does more than this
but i wont ruin it . You may have to go on amazon.com to get the older versions.