Picked these up not too long ago, and they are wasted on me. Thinking of selling or trading them, and wondering what they might be worth. All are in excellent condition all around, complete with original inserts, trays, manuals, and I think they all even have their baggies. I don't follow GB stuff, and don't seem to see boxed examples on eBay (or anywhere else) for reference.
Mortal Kombat
Super R.C. Pro-Am
Kid Icarus
Tetris
Tetris 2
I had this picture handy from when this was a find, so for what it is worth: