Have all the Vegas shows and the one at Disney in Orlando (La Nouba). O is by far the best. If you will be back in Vegas anytime soon, I agree with PTravel about seeing Mystere first as a good option. Mystere is still a great show and all the other Cirque shows I have seen are really good, but after seeing O first, nothing has quite lived up to it.

In terms of seats, I got my O tickets at the Bellagio website (they used to go on sale 3 months ahead of time for hotel guests, 1 month for other folks - not sure what they do now) and had almost the last row in the upper deck. The view from the top was still amazing.

And fyi, the Towers rooms at Luxor are not that bad if you can swing them.