I am a fan of Orvis beds. They are pricey, but they are generally of excellent quality* and last forever.
*I had one unfortunate incident the last time I bought a round of bead-filled dog beds where the inner liners all broke so when I tried to take the covers off to wash there were beads EVERYWHERE, but they not only replaced the interior of the beds but sent me some more durable liners for free to put over the replacements before putting them in the covers in case they broke again.