Yeah, Boards of Canada served as my introduction to IDM a few years ago and they have been my favorite ever since. I've got most all of thier music AFAIK, which albums do you have? Plaid is my 2nd fav, like I said Spokes is excellent, songs 4-7 are amazing IMO. Trainer is a double cd set, and the variety between tracks is amazing, IIRC it's a compliation of old and new tracks. Rest Proof Clockwork is another great album, much more melodic on the whole. I love most anything by µ-Ziq too, Brace Yourself, Tango and Vectif, Salsa with Mesquite, Bluff Limbo and esp. In Pine Effect. I never really took to Mira Calix, but I may have to give them another listen.
Amon Tobin is great too, his tracks have a real instrument / DnB sound to them that I really dig. I haven't heard Tosca Suzuki before.
Have you ever checked out Warp Records Bleep:
http://www.warprecords.com/bleep/
It's an online music store where you can sample the entire collection and buy MP3's or CD's. It's great!