I collect consoles and I can honestly say every system I have has been worth buying even if its for a couple of games. But unless you are die hard about getting the original hardware emus are a great way to try systems out before you dump money into them. The only system I want and can't imagine any really good games to justify the cost is Philips cdi. Other than that, get a Atari 5200, 7800, and jag, intellivision is way fun same with colecovision (if you have make you can skip these), turbo grafx has tons of great games especially shmups and for what the system and games cost I haven't struck out yet, the genesis addons each had a few nice gems, sega saturn is a great buy, and pretty much anything console you can find atleast a few games you will enjoy enough justifying the costs.