Wikipedia is your friend:
(see also the articles on the 1st, 2nd generations to see how we got there).
Also, just FYI as it seems to be a common point of confusion, note that 8bit games consoles and 8bit graphics have different meanings.
As for favorite 8bit games, I think for me most of my faves are from the 16bit era (SNES), but of course the early Marios, Zeldas and Castlevanias etc… that are still franchises today.
I realized that generally people use 8bit and 16bit to refer to consoles, so I’m not sure if you’re also interested in PCs as well. (Going back that far, the definitions get a bit hazy anyway).
Imho the first real ‘pc’ as we think of it today was probably an IBM PC/AT which had a 286 processor (16 bit).
But there were lots of home computers / micro computers / personal comupters before that that were probably 8bit. Not sure how much they were used for games… probably depends on the type.
(Seems like Apple 1s and 2s, BBC micros, Commodore 64s etc… all had 8bit cpus. https://en.wikipedia.org/wiki/MOS_Technology_6502#Computers_and_games ).
I’m not clear on the versions of the BBC micro, so i don’t know if they were all 8bit… but if so, my fave 8 bit games were all the ones I played at school:
Chuckie Egg, Elite, Thrust, Repton, and probably Exile as my fave.