Fair, I would go:
1. Tri-state 1925
2. Piedmont 2011 (probably good argument for top 1)
3. Bridge Creek 1999
4. Jarrell 1997 (this is definitely number 1 for damage alone and considering it may not have actually been that slow based on recent revelations, could get that spot for me)
5. Moore 2013
6. Smithville.
As extreme as smithville was, I personally dont see any argument for it being top 3 at least on the damage end of things, and as for tri-state it was moving even faster than smithville was yet produced such extreme damage for such a long time.
I agree with Western though in that ranking tornadoes is splitting hairs and quite pointless honestly, at 200+ most things are gone anyway.