I am running 4 GTX480's in SLI, and even the 2 middle cards never break 95c during benchmarking/burn in. These cards are superclocked as well, with stock cooling.
I build gaming rigs as my 9-5, and I NEVER see 100c+ temps on ANY card, unless something isn't setup/optimized correctly. I've been building systems for the last 15 years, here are the most common/overlooked things I've encountered that can elevate GPU temps.
In no particular order...
1. Improper GPU overclock/voltages.
2. Bad fan control settings(this is VERY common with Nvidia cards. The fans dont fully speed up untill about 90c, which is far too late. Use Ntune,(or equivalent) to setup a custom fan profile, that forces the fans to 100% when the card reaches 80C, or just set the slider to 100% before a gaming session.)
3. Some power supplies suck cold air from outside the case, then internally expel hot air upwards, toward the GPU/PCI slots. (very commonon on older PSU's) Sometimes the PSU can be installed upside down, and just needs to be flipped, so that the hot air is directed downward.(make sure your case has vents under the PSU, and that your computer isn't sitting on carpet)
4. The computer is too close to the wall/desk behind it. This creates a superheated area between the computer and whatever area/wall it's located next to.
5. The blades/fins on the GPU fan appear clean, but internally the VERY small channels/fins that direct the air through the heatsink are blocked, or severely clogged. (very very very common if you own a pet, or the computer sits on carpet. The hair/fibers bypass the fan, and then snag on the heatsink fins)
6. Airflow into/out of the case is not setup correctly. The lower fans should be directed to suck in cold air, and the fans on the top half of the case should be directed to blow hot air out. This follows the "hot air rises, cold air falls" rule... (this easy fix can drastically lower internal case temps, and remove any "stale air" that might be recirculating, due to the fans fighting each other, instead of working together.)
Goodluck!!!