I definitely think it is because it is a pick up and play game that has simple rules so anyone can learn in a matter or seconds. I find puzzle games, when done right, to be absolutely addictive. I think the best puzzle games are Tetris (no duh), Bust-a-move, Lumines, and Dr. Mario. I know there are a few more but I don't know the names.
The best version, EASILY is the NES version. The Gameboy version has nothing on it. Being able to play it at home in all 30 inch glory back in the old days made this easily the best. I think Tetris DS's new rules are interesting, hugely unfaithful to the original, but acceptable changes. Tetris DS certainly makes the game easier, and I've been playing it a lot.
It was maybe 8 months ago that I played a game of Tetris DS for 12 hours, straight through the night. Living proof that the changes made the game too easy. The changes are GREAT for multiplayer, but the core game became kind of dull.
PS. Do you guys recognize the blocks by shape or color? Ever since Tetris DS I've been relying on color, and it annoys the hell out of me when I play another version of Tetris with different colors because it throws me off so bad, especially when they retain the same colors, just they are for different blocks.