Abec11's Biltin bearings have been an open secret for a long time. Sought after for their integrated half-spacers and washers, these are a solid and easy to service bearing that will run and run. They even come affixed to a bolt in a dedicated tube which is designed to facilitate easier cleaning; just replace them on the bolt after a session, pour in some rubbing alcohol, citrus cleaner, or surgical spirit, and shake them clean.

(Make sure you relubricate them before you put them back in your wheels, though!)