I just brewed one up this weekend with WLP036 - Dusseldorf Alt Yeast. White labs says it creates clean slightly sweet alt beers. I also picked because it has the same attenuation range as the bavarian lager strain.
A lot of people recommended Kolsch or Nottingham yeast, but I didn't want my Aletoberfest to over attenuate and be left too dry.
I have read on here people have a lot of success with S-04, Nottingham, and Kolsch yeast keeping the temps on the low end.