For background:
Longsword: +3, d8, versatile
Double Sword: +3, d8/d8 (looses versatile)
Flail: +2, d10
Double Flail: +2, d10/d10 (doesn't loose anything)
Battleaxe: +2, d10, versatile
Double Axe: +2, d10/d10 (looses versatile)
And now we have:
Scimitar: +2, d8, high crit
Double Scimitar...