I say Jeff Jarrett goes in first. Guy deserves it the most, but not sure how much he is still planning to work in TNA down the road. If he plans to come back as an active wrestler (say more than 3 - 6 months out of the year) then they should give Sting the #1 spot.
Best thing they could do?
First inductee should be Jerry Lynn. Use his "retirement" announcement to put over the X Division. State how the X Division is what gave TNA the ability to get the national attention they garnered and is what put TNA on the map. Build how if it wasn't for the matches Jerry Lynn was a part of, TNA could have never made it to the "Number 2" source for pro wrestling in the United States. Just go all out giving the X Division credit back for being what made TNA so much more entertaining to watch. From there, they begin featuring X Division more and more and get back on track with where TNA was in '08... Damn, I know I'm a daydreamer but that's far out there even for me.