Total Recommendations: 2
National stereotypes (or girls acting out national stereotypes, as is the case for girls und panzer) fighting in a tournament. Difference is Girls und Panzer stays as a tournament while G Gundam turns into a save the world thing at the end.
Aside from also dealing with card games, 5D's is generally more serious than it's predecessor, yugioh GX. This is similar to Brave which is more serious than the anime before it, Battle Spirits Shounen Gekiha Dan.