In terms of pure skill, Akrigg is definitely one of the best. Others that have amazing skill and capability on a bike are:
Gee Atherton: DH, Red Bull rampage, dirt jumping. Pretty much excels at everything.
Brandon Semenuk: Amazing on a bike full stop. BMX to DH, he can do it all.
Kyle Straight: Hugely skilled on a bike. One of the few freeriders who is fast enough to compete at top level DH.
They might not be the most well known, but these guys are at the top of the game when it comes to skill on a bike.
For the guys that are legends of racing, it would have to be Peaty, Minnaar, Lopes and Graves.
Best overall? Probably Gee Atherton.