PokerTris is a great remake of a never-released Nintendo game called Super Square Deal (see related link below to get that game).

Alexei Pajitnov's blockbuster Tetris spawned many clones, but Puyo Puyo is one of the more worthy derivatives from the whole falling-blocks craze in the early 80s.

Puyo Puyo 2 is a great sequel to Puyo Puyo, one of the best Tetris-style game that inspired numerous clones on its own.

Puzzle Beauty is a so-so Tetris variant developed by Dynasty International, famous (in Asia) Taiwan company whose Flame Dragon series consistently rank among some of the best-selling games in Asia.

Decent conversion of Taito's coin-up puzzle/logic game done by Banana Development, an independent studio that ported a lot of arcade/non-PC games to the PC.

This is a a good Tetris variation with difficult computer opponents, each with unique playing style.

RoboCrush is an excellent Bust-A-Move-style game from Freeform Interactive, the now-defunct company behind the popular Ingava.com freeware site.

Squarez resembles Tetris in a sense that you must assemble sets of blocks in specific patterns so that they dissappear to make room for more blocks (repeat ad infinitum if...

Stack-up is a little variation on the well-known and often copied Tetris type of game.

Stackopolis is one of the most creative Tetris variants I have seen.