I have amassed way too much Sega Genesis Hardware over the years. And as the price has gone up here is some knowledge if you are thinking about owning sega hardware.
Prices have went up quite a bit in the last 10 years. Hard to find a deal on EBAY anymore. Sometimes Craigslist you can get a steal but the resellers normally gobble them up first. Those chain Goodwills know the prices on these as well and sell them online instead in stores.
If buying on EBAY "No cables to test sega, as is" means it doesn't work
Gamestop has went back into retro sales and their prices are competitive if you want to buy now instead of searching for a deal.
Try to stay with OG Consoles, Controllers, adapters etc.
Most third party stuff is crap
The 3rd party 2-1 Consoles I bought was horse poop. couldn't play all the games and controller pad broke after 1st week. Think the brand started with a "y"
Main 3 party offenders
https://www.amazon.com/Generic-Classic-Genesis-6-Button-Controller/dp/B01LYRONFT/ref=pd_sbs_63_t_1?_encoding=UTF8&psc=1&refRID=V3CFQXJ70P32EE216VMK These Controllers break within the 1st hour
https://www.amazon.com/AC-Adaptor-Nintendo-Super-Genesis/dp/B000F0QJIM/ref=sr_1_1?s=videogames&ie=UTF8&qid=1489499379&sr=1-1&keywords=3+in+1+power+cord these 3 in 1 adapters won't power up a Sega Genesis 1 even though they are sold that way
A Nintendo AC Adapter will power up your Sega Genesis 1 but it runs on different current and will eventually fry your sega
Sega 1 Power AC adapters and Sega 2 POWER AC adapters are not interchangeable, same goes for TV hook ups.
These TV hookups are great! Much better than the COAX for picture quality https://www.amazon.com/Sega-Genesis-Standard-Cable-Bulk-Packaging/dp/B002FY0CM0/ref=sr_1_1?s=videogames&ie=UTF8&qid=1489499476&sr=1-1&keywords=sega+genesis+tv+adapter
New Flat Screen TV's play the game faster than a CRT.
I'll post more as they come to me and others feel free to put tips here as well.