15/27
This build. Grab a longsword and go to town.
Alternatively, you can go 12/27 and get 9 WM. The extra 50 wpf works out to only 0.5% less damage than the 5 PS build. While WM is normally a fairly useless investment, stacking 9 of it definitely seems to make a difference. The disadvantage is that there isn't much 2h variety available with strength that low.
If you max your speed bonus, hold up to 0.5s, and aim for the head whenever possible, you'll do a lot more damage than people expect. Just remember that speed bonus works both ways.
Another option is a 36/3 STF with a cudgel. People will assume you are a peasant, and will be careless when fighting you. You can then proceed to beat the crap out of them (a cautious / good player will dance circles around you however, so it's gimmicky).