Looking through my purchase history, not many:
Combiner Wars Groove
AOE Strafe
AOE Slog (G1)
Generations Hoist
Generations Metroplex
G2 FOC Bruticus
25th Anniversary Unicron
I've bought quite a few TF books throught Amazon though. Several of the IDW Collection hardcovers, the Premier Edition IDW Hardcover, How To Draw TFs, the Art of IDW. I also bought the TFTM Score CD from them.
