Go with the Avalanche. Especially if you do not need the third row seating or so much back seat. Besides you have a pick up and SUV all in one. You can use this thing on camping and other accessories like the back cover so it looks like the tahoe if you want. Also, the Avalanche is a bit more unique than the Tahoe.
I drove both vehicles, and they feel pretty close but I still prefer the Avalanche.
Also, the avalanche has two ice boxes in the back that drains itself. Thats pretty awesome. Plus you can either tell people you have a SUV, Pick Up, or a SUP. lol.
These are both choices. But Avalanche will feel more like a dream than the Tahoe.
Oh and if you can get it in Black on black leather. Get all the options. Thats pretty awesome. If you can consider the Z71 Avalanche with the LTZ options with it. Its about the same price.
And wait until August to purchase, like mid August because the price will go down a bit, since Chevy should be bringing out the 2011.
