SMC 50/1.4
Ricoh 55/1.4
Vivitar Series 1 135/2.3, 200/3, 90/2.5 Macro, 70-210/3.5 (ver 1)

The 50/55 lenses cost me about $15 each and the Vivitars were all under $50. I use them on either a Spotmatic or Ricoh TL or with an M42/K adapter on either a Chinon CP6 or Ricoh XR1. Mt favorit lens is the 135/2.3.