• The Best Version of the Genesis - Buying guide on Retro RGB.
• GUIDE: Telling apart good Genesis 1s and Genesis 2s from bad ones. - Buying guide on the Sega-16 forum, has most hardware variants.
• https://consolemods.org/wiki/Genesis:Buying_Guide Buying Guide - Buying guide on Console Mods. Detailed, with lots of photos.

• I want the best audio chip.
• I want 60Hz.
• I want the best compatibility, but this is almost universal.
• I prefer the original design to the Mega Drive 2.
• I don't want to have to mod shit.
• Step-down aren't needed, can just buy AU AC adaptor.
• Not super fussed about video quality. All support RGB, some models I don't want anyway have jailbars.

The basic, foolproof, guide is: If you're buying a Genesis get a Model 1 with the EXP port on the back. If you're getting a Japanese Mega Drive get one with the text 'AV Intelligent Terminal' 'High Grade Multipurpose Use' on it. Don't buy a PAL one. If you want to fuss over details and try to get a bargain check the guides linked.

Controller selection is pretty boring!

The best standard pad to get is the official six-button controller. I don't like the three-button controller, but it feels weird playing a Mega Drive without one. Haven't tried any third-party ones, but have heard good things about the SG Propad (SNES-like) and the Tetsujin controller (red/blue/purple buttons). Hori do a Mega Commander pad.

For joysticks there aren't many options. The Japanese versions of the official sticks (Arcade Power Stick) are decent, the non Japanese versions don't have microswitches. There's a version of the Capcom Power Stick Fighter, but it's pretty pricey. The colours are nice.

There are some famous Micomsoft controllers, their two variations on analogue controllers the XE-1AP and XE-1AJ. The XE-1ST2 and XE-1SG should work(?), but they're only three buttons anyway.

• https://www.mega-drive.net/mdpads.htm
• https://www.mega-drive.net/mdsticks.htm