No joke: the recent LCD version from McDonalds in China. (Shaped like a McNugget, look it up!) It's a ridiculous object and gameplay is honestly pretty bad, but I leave it out and end up playing a couple of times a week.
Tetris DS is also a nice choice! It was the first time I saw gameplay beyond simple A-Type and B-Type, possibly my first online Tetris play (or maybe that was TetriNet). Good memories of that one, have fun with it!