Almost six years after its release, I'm finally ready to take the plunge and get a PS2. However, I much prefer the original, bulkier model, so I guess I have no choice but to get a used one. So, which serial number(s) should I check out for/avoid? (Is there a particular model that has a much better reputation (less noisy, less DRE prone, etc.) than the others?)

P.S. Oh yes, I don't intend to have it modded.