For a house yeast for American-style ales, I'd go with trusty ole Wyeast 1056 or WLP001. The yeast is a beast and it always chews through wort at a good clip. I usually get 80% apparent attenuation or a little higher if a portion of the fermentables is sugar, even with big beers like barleywines that have O.G.s of 1.110-1.120.
For Belgians, you should checkout The Yeast Bay Northeastern Abbey
and Dry Belgian Ale
. I have used the Northeastern Abbey with great success and the Dry Belgian Ale I'm currently using is chugging away. The Attenuation on the Dry Belgian Ale is reported to be very high and on of the beta testers for The Yeast Bay reported 100% apparent attenuation on his trials
. Before The Yeast Bay, I used Wyeast 3787 with a lot of success for all things Belgian.