Big ups to Kotaku for this:
http://www.amazon.com/exec/obidos/ASIN/B00066LG60/ref=nosim/seganer-20
It's basically a mini Genesis plug and play with one controller, Sonic 2, Ecco the Dolphin, Gain Ground, Columns, the Ooze, Alex Kidd and the Enchanted Castle for $9.99 plus shipping (originally $29.99).
I didn't see it posted already, feel free to delete if it is.
http://www.amazon.com/exec/obidos/ASIN/B00066LG60/ref=nosim/seganer-20
It's basically a mini Genesis plug and play with one controller, Sonic 2, Ecco the Dolphin, Gain Ground, Columns, the Ooze, Alex Kidd and the Enchanted Castle for $9.99 plus shipping (originally $29.99).
I didn't see it posted already, feel free to delete if it is.