Yess -- I second the gondolas at the Venetian! Ha, some of the gondola-men will sing for you too.
There's two Sephoras at the Venetian, one of them is almost as big as the one in SF, there's also one in Paris.
And like a lotta people said check out the forums at Caesar's. I looove Caesar's -- you definitely gotta stay there once. The premium rooms are freaking great!! Ha, I like the showers in the suites. And the pool is beautiiiiful. Same with the one at Mandalay! I have yet to stay there, but everyone should stay there at least once.
Check out the beautiful garden in the Bellagio as well -- a nice place to stay next time too, has a beautiful pool.
Be sure to check out the different BCBGs throughout Vegas; they always have good deals.
Overall, I mostly suggest that you try the bars (Dunno about the club/lounge-type bars) and restaurants around. The ambience is so alive.
Also, lol don't go to Fremont. It's cheesy, old Vegas. Unless you really wanna try.
And there's always Chippendale's in Harrah's.
Ha.