Well i don't know if i answer this completely correctly since there are a lot of Yu-Gi-Oh! games out there but i will tell you which ones i know:
Yu-gi-oh! World Championship 2004 through 2010
Yu-gi-oh! Tag Force 1 through 4
Yu-gi-oh! Capsule Monster Coliseum
Yu-gi-oh Duelists of Roses
Yu-gi-oh! Joey, Yugi and Kaiba
Most of the other Yu-Gi-Oh games are either for Gameboy Advance and most others are Japanese.
Unfortenately it can only connect to itself not other WC Games
if you mean online pc games theres kaiba corp, yugioh dueling network thats all i know
Best place to watch any episodes of Yugioh, Yugioh GX, Yugioh 5D's, and Yugioh Zexal is at the website 4kidstv.com
yes,yugioh 5Ds Wheelie breakers
yes yugioh is math it includes adding, subtracting, multiplying and, even dividing if you ask me i would say it is one of the best math games plus it teaches you a lot of things
Series after: yugioh 5'ds is yugioh Zexal.
you can find yugioh games in gamestop. I only saw DS games but maybe i wasnt being observant enough
the same as any of the other yugioh wc games if you look at the bottom right of any yugioh card you will see the code for that card
There are no officially supported sites that you can play for free.
yugioh network
Go to Yugioh-cards.com to check for updates when new tuornament on yugioh 5'ds be out.
yugioh zexal in Spring 2011