I used to be a big fan of Wyeast 2035 American Lager, but it's one of the Private Collection limited release ones now. Haven't used it in years, but it might have been the first lager yeast I ever used back in the early 90s and I really liked its character. It supposedly came from August Schell in MN, which long advertised their special house yeast saved from before Prohibition, but I've also read that in recent decades they've switched to different strains, acquired from different breweries, for different beers and under different conditions. Worth trying whenever it comes around, but I don't know when that is. You can never go wrong with good old 2206 though. My current go to yeast, although it's German and not American.