To me, Twilight Princess has always just been a possible Zelda game- not amazing, but not awful. I found it to be fairly bland overall. I don't hate it. In fact, as mentioned by TC, I enjoyed being a wolf, the hidden skills and other secrets. Dungeon design wasn't bad IMO. But overall, it felt sub-pair the rest of the series. Mainly, I just felt the game was seeming uninspired, and only made to appease those who disliked Wind Waker.
It was the first Zelda I had played in YEEEAARS... I finished ALttP like fourteen times when I was little, and the jump to 3D was awesome. When I replayed it after SS, I realized it is a very dark game... Not just in terms of graphics. In SS, you know Zelda is alive, but in TP SPOILER ALERT there is a very real possibility that Zelda dies saving Midna.
I hated howling! That was worse than the harp in SS. >.>
But, overall, my 2nd favorite.. to ALttP.
Twilight Princess is a very interesting case. It wasn't the best game in the franchise but it didn't need to be. Twilight Princess stayed true to the fundamental aspects of the franchise and even improved on some.
Twilight Princess came at a time when most fans were doubting Nintendo. The Gamecube was definitely cutting edge technology as the Spaceworld 2001 demo showcased, however, it seemed that the company was heading in the completely opposite direction with The Wind Waker. Sure previous Zelda games were rated "E" for everyone but their style and content especially the original trilogy and Majora's Mask were directed towards a more general even mature audience. The Wind Waker seemed like a truly "kiddie" break from tradition. In retrospect we all know that wasn't true but that's what it seemed to exaggerating fans at the time. It's no surprise then that the announcement of what would be Twilight Princess brought so much craze at E3 2004. Whether or not the game fulfilled on its promises, however, is a different story entirely.
Despite being somewhat different than its beta version, Twilight Princess in its final form retained the gritty characteristics it had when it was first announced over two years before. The game wasn't shy to include sexual references with such characters as Ilia and Midna throughout. It's also been long disputed whether there actually was blood shown upon Ganondorf's death. But let's not get off track as that information is superfluous in regards to this thread. Twilight Princess had a staggering 10 dungeons if you count the Cave or Ordeals! That's a big deal. Only A Link to the Past had more dungeons. And it wasn't just quantity, it was quality. Despite fan complaints, the puzzles in Twilight Princess were top notch and arguably better than those with which the title gets the most direct comparisons-Ocarina of Time. Bosses were massive, of a scope never before seen in franchise history and certainly for the better. The overworld was connected and diverse in the variety of regions to explore. It was also nice to take a romp through Hyrule ridig on Epona once more. Twilight Princess may not be my favorite installment but there's no denying it's not only a great Zelda game but also a fantastic videogame.