I had a megadrive and a friend got a mega CD for xmas. It was one of the frontloading ones - looked pretty damn cool for the time.
He had a couple of games, perhaps sewer shark and a flight game - thunderhawk i believe.
I don't know why, but i decided to get one. It wasnt exactly like I thought it looked better (infact the grainy video wasnt good back then),
So anyway, i bought one for £180. It was actually the Mega CD 2. It looked a bit cheap but it worked. It came with a copy of Road Avenger and that 6 in 1 sega cd that I don't think i ever even bothered to play.
I did enjoy Road Avenger, but by the next day I had finished it. quite a easy game but was fun.
Later that night my brother got a bit angry and punched the mega cd 2. It died.
Thankfully it came with a reciet for dixons so we managed to get it swapped

Happy times.
I ended up getting several games for it - sherlock holmes was a waste of money, I thought it was awful.
Sonic CD was decent, although I only ended up borrowing it of a mate for the summer holidays.
Night Trap was probably my most remembered - still remember going to buy it from the local paper from a guy with a slot machine in his room. "I dont think your kid should be playing this, its age rated". I still did.
Again, it wasn't the best game - had it finished pretty quickly but kept entertained for a little. The game was a bit pointless because if you want to beat the game you have to miss anything actually entertaining happening.
I ended up buying a magazine that had a demo game on each month. Don't see that much anymore! generally none of the games peaked my interest though - silpheed was quite nice, soul force(sp) was quite a nice star fox style game, wasnt as good though.
I ended up selling my Megadrive & Mega CD down the line - i ended up getting conned by someone using a fake cheque. Never did get any of my money back. Think the bastard got sent to jail though as it wasnt the only "job" he did.
Got a Multimega about 10 years ago - had some fun replaying old games, but last time i tried to use it a few years back - it appears that something has failed as the cd doesnt spin.
In any case, i enjoyed the few games i played on it - but quite a big waste of cash on my part.