I like ATMEL AT89Sxxxx series. Reasons.

1. No additional chip such as MAX232 required for ISP purpose. [ With some of philips you need MAX232 just for ISP even if there is no other use of it ].

2. No silly things like this pin should be held low, that should be held high etc. etc. while ISP.

3. Very reasonably priced AT89S51 [ Rs. 45/1$ ] AT89S52 [ Rs. 55/1.2$ ]. Easily available even in small quantities.

4. Very much suitable for my Automation application where even 4MHz is far more than what I need.

Regards,
Prahlad Purohit