Hi,
Microship have a lot of different micros (all in flash) 16F870 it's easy to use and very cheap about EUR3/4.
If you need more power, you can think about SX20 (very like 16F84) that can reach 50 MIPS.
Another bood choice and very, very cheap its Motorola HC08 Nitron (about only EUR 1/2. A...