Well we started off with playing God of Battles in 15mm. It played well until we'd ended up playing it so much that we began to find various loopholes and weaknesses in the rules and then it sort of lost our attention. We decided on 15mm because you could get a decent sized force relatively cheaply and painted up relatively fast. Plus we'd been playing 15mm scifi for a while and enjoyed it, so why not fantasy too? I started with a beastman army (played as Blood Gorged in GoB), and finally got them all painted just as our interest in GoB was beginning to wane.
However, my interest in 15mm fantasy didn't stop there. Having seen the Demonworld range by Ral Partha I was hooked. The advantages of having a small table easily set up, with characterful minis that were lovely to paint got my interest going and I found I was hooked to 15mm fantasy skirmishes.
Regarding rules I/we have tried Open Combat, but found the moral rules clunky; Skulldred, which had potential, but then Dave King disappeared and interest dropped. Having liked Open Combat, which is inspired a lot by Bloodbowl, we went back to the source and played around with the Bloodbowl rules and they seem to have stuck so far.
But anyway, you guys are probably more interested in pictures of painted minis rather than my ramblings. So here's my first offering. There's more painted, just not photographed yet. My photography skills aren't the best, but I hope you get the idea.
A skirmish force from the Beastmen I started with:

The Boar ridder is a conversion from an old Citadel/Marauder boar and the big beasty is a Reaper Bones mini.
An Orc warband

A wildman/frontiersman warband.

And lastly, a wizard and town guard

Hope you like them and feel inspired to share your projects too.