Sigma EF 530
I've got a Sigma, and I've used it with good success with both an A200 and an A350. I also had good success with ordering a repair part (needed due to damage due to use in a crowd situation, not any product defect). It saved a significant amount of money vs. the Sony unit.
Tamron 70-200 SP AF DI-LD 77mm, Tamron 70-300 58mm, Minolta AF 50, Minolta AF 100 55mm, Sigma 20-70 52mm, Tamron 200-400 77mm, Tamron 28-300 XR DI-LD 62mm, Tamron 28-80 58mm, Minolta AF 70-210 55mm, Tamron 1.4 teleconverter, Sony 75-300 55mm, Sony 18-70 55mm, Sigma EF 530 flash, Canon S3.