Heres a top 100 (as voted for by sega8bit forum members)
There are 10 card games (in the west)
Spy vs Spy
F-16 Fighter ('F-16 Fighting Falcon' in the US)
All of thease were later made available on cartridge - allthough Great Soccer is actually a different game on cart.
As for the games built in, it depends which model number it is.
The first appears to have no game but infact has a hidden Snail Maze game. The next release had Safari Hunt and Hang-On, then ther was Missile Defense 3D and then Alex Kidd in Miracle World. The SMSII also had Alex Kidd in Miracle World and later it got Sonic.
In Brazil they are still bringing out Master System's, but with more games built in. Last year the 131 game version was relased. On the later ones there isnt a card slot (allthough they look the same other than colour). The last Master System to have a working cartridge slot was the 112 game model, produced in 2005. Also just for an info overload the last game released on cart was Mickeys Ultimate Challenge in December 98.
Anyway the SMS is a fantastic system, i'd recomend Alex kidd in Miracle World and Shinobi World, Wonder Boy III The Dragons Trap, Putt and Putter, R-Type, Power Strike 1 & 2, Sonic and Castle of Illusion.