I have never met or raced against Thomas Turner PRO (Outspokin) but I do like to admire him from afar. It seems that no matter the length or intensity of the race he is always a contender. Even after a bad crash and shoulder injury this summer he came back strong for the national MTB championships and now in the Fool's Gold 100 MTB endurance race, placing second to Jerimiah Bishop. In the local MTB series he is somewhat without peer and even in takling a stab last year at cyclocross he showed he can win races and place high in the series. He is also a douoble GA single-speed champion in the open category and set the course SS record last year at Ft. Yargo. I look for him to tri-peat this year.
Greg Turner (no relation) is also a massive talent. A local/regional legend, whose name invokes groans from others in his race, shows year after year he can win a various distances and disciplines. He has used his abilities to win cyclocross, road and MTB races on a consistant basis in the masters category. He is also a GA SS champion in the marathon and just placed 1st on the SS in the Fool's Gold. It would be wonderful to see the Turners battle in the SS championship.
Jason Chapman and I first crossed paths in cyclocross and he was racing only on a single-speed cross bike and dominated the B race series. In fact, most all he races is either single-speed or fixed gear. He is the fixed gear SS MTB champion in Georgia and when he races I am always amazed at his speeds and his gearing on the SS MTB.
Shey Linder organized the SS championshups in GA, is a co-promoter of the GA CX series, Pro MTB racer and likes a lot of endurance distances races. He is quiet and reserved but on the bike I would say not laid back. He is very competitive and if he is not winning, he is placing very high. Besides his racing, his training and judgement about a lot of cycling related issues is invaluable. Because of his leadership and skill he is one person to definately have on your team.
Shane Schreihart races expert MTB and endurance MTB mostly on a SS bike. He takes on all comers in the expert division on the SS and seems to not care what gear(s) you use, just that it is a bike and it rolls. His high placings on the SS bike against fellow geared riders is impressive. He is also very mentally tough as displayed in a 12 hour MTB race (Dirty Spokes) last spring where he did 12 hours on the SS.
"Markie Mark" Stewart is another MTB racer who after performing at a hig level for years, picks and chooses his races now and many of them are distance endurance races. He has a great tactical sense and is also great at pacing. But, (like Shane) his mental toughness really impresses me also. I have never seen him give up and he always seems to maintain a positive attitude in ther midst of suffering.
There are lots of other folks who might make your list, and probably a few I have left out here (no offense). These are just a few that have stood out to me this year.