Recommended: Beyond Oasis, Kid Chameleon, Landstalker, Shinobi series, Phantasy Star series, Shining Force series, Streets of Rage series, Super Monaco Gp, Sonic series, Decap Attack, Outrun, etc. Cons: Few options for RPG games.
Serious classic. It came with Sonic the Hedgehog 2 when I bought this. Fun times. You can find updated Sega games on Nintendo and Playstation platforms. Cons: You can't really get a Sega Genesis nowadays.
The best video game console ever made. Great games (Sonic 3 & Knuckles, Super Street Fighter, Dynamite Heady, Streets of Rage, Comix Zone, a long etcera). A classic Cons: Difficult to find a new one. Maybe you'll better search a good emulator or download the games from the classic repertory avalaible online in newest consoles.