Much like Link to the Past, a perfection of the elements seen so far.
All the classic elements are here, a fresh variation on the plot that's to be expected since Ocarina, a larger world, without the tedious overlarge areas of Wind Waker, puzzles, dungeons. All polished to a mirror sheen. What's more important however, is what is new.
Apart from the new Wiimote controls, the scale of everything has been amped up to a new level. Bosses are even larger affairs, and though some are easy, they're all fun and take just the right amount of time to beat. You might say there's a Shadow of the Collossus influence in these bosses, but it works for the best.
One of the other things Twilight Princess does well is its story. While Wind Waker had provided some interesting variation, Twilight Princess goes back to roots in some ways an advances forward in others. In particular, Midna is the most interesting character in Zelda canon so far, serving as a great replacement for the usual fairy.
As for negatives well, if you're not a fan of Nintendo rehashing older elements, stay away from this game. This is probably the final installment that will maintain this older style of gameplay before Skyward Sword, but it does an excellent job of it.