Avoiding countless Stickies, due to the high quality on ATT, here is a list covering some of the best models on ATT. Should you have a nomination, please PM one of the moderators and we will discuss adding it.
Warhound's Truescale XV8s
Firewarrior Tutorial (Cire Mont'yr's army)
The Long Tau Project
Kaka_u's Cadre (Bold colours, striking crispness)
T'oturi's Chosen Cadre
D6 Veteran, Mont'au Mechanised Cadre
Ma.K Maschinen Krieger SF3D Exhibition - Kai'lore
Xeones' Piranha Conversion Gallery
Jutami - "Target aquired, intruder battlesystems deploying in 3,2...
WIP (Weathered) Farsight Cadre
Tyto's Cadres WiP Blog
Tyto's a new way of painting (good weathering guide)
Mattr's new tau army Pictures of both WIP and finished articles.