Duel Masters, on TV Tokyo
ANN; IMDb; Toonami Wiki; TV.com; TV Tropes; Wikia; Wikipedia
The show is about this card game called Duel Masters, which is a total rip-off of Yu-Gi-Oh!, except not as interesting. The main character is this kid named Shobu Kirifuda. Of course he's got some friends who go along with him. One of them is this geeky little guy named Rekuta (a running gag is that he's often knocked flying, Team Rocket-style). Other friends include girls named Sayuki and Mimi. Then there's this guy named Knight, who is sort of Shobu's mentor, I guess. And then, sometimes people Shobu battles and beats become friends. And there's this place called the Temple, which is full of powerful duelists Shobu has to beat. Also I should say that some card battles are called Kaijudo battles (from "kaiju," which means monsters), in which the monsters on the cards come to life. Very few duelists are able to engage in kaijudo battles.
I'm afraid I can't say too much about the storyline, I haven't seen all the eps and stuff, but it doesn't matter much. Nor do the card game itself, or any of the battles, as far as I'm concerned. What matters is the dialog, the banter, both in and out of battle. It's so intentionally ridiculous that it's hilarious, full of pop culture references, plus characters frequently breaking the fourth wall (making reference to the show being a show), and stuff like that. I've always loved that kinda stuff. And that's pretty much the only thing that truly makes the show watchable. I enjoy the show, just for the banter (which is way better than all the serious yakking they do on Yu-gi-oh, though on the whole I prefer that show). And that's about all I can say.
Well, various stuff happens after Shobu beats the whole Temple, including the best duelist there, Hakuoh. There are more characters to meet, defeat, and befriend. More battles and adventures. Shobu and Rekuta eventually travel to all the monster civilization lands so Shobu can become a better kaijudo duelist like his father before him, and also defeat an evil organization called the PLOOPs. But whatever adventures there are, the series always eventually goes back to just regular sort of duel tournaments. Though there may be bad guys to face in those, too. The third season (in America, but the second season in Japan) is called Duel Masters 2.0, and most of the voice actors are different, which is really hard for me to get used to. Plus one of Shobu's old rivals, Kokujo... well everyone now pronounces his name differently than they used to. Of all the new voice actors, I suppose I'm getting most used to Mimi's new voice, which is done by the actress who plays Suzy in Zatch Bell. Anyway, I think the show moved around in the schedule so I couldn't keep up as much as I'd like to have done, but I didn't always make the greatest effort even when I knew when it was on. It's not that important, but... meh. It was fun for what it was.
There was later an American reimagining of the show (very different, more serious), called Kaijudo: Rise of the Duel Masters, which I think is much better than this.