I'm very happy to see the Denizen figures being redone as 28mm figures but I'm now thinking about other ranges that would benefit from the same treatment - the old 'Spacefarers' range for one; they were a very nice range of figures that I'd love to see again in 28mm.
It's mostly fantasy, but I think almost any classic figs by Tom Meier could be scaled up to 28mm and compete with current ranges.
I don't know who sculpted them, but the long OOP Ral Partha AD&D Black Sun range would be fantastic to see on 28mm.