The tiny25/45/85 26/46/86 are all effectively the same part. The odd part numbers are 8pin the evens are 20pins The 2/4/8 is available programming memory, also from low to high it's 128/256/512 bytes of eeprom and SRAM each.
I like them all. But I have to say the 18f1220 which is just less ram then it brother the 18f1320 I like the best It easy 18fxxx chip to start with and I don't need a lot of pins to control two motors and some Ir sensors. But the neatest thing I did with it was a combination lock with 3/4 keypad and a light dimmer.