I spent a lot of time in the arcade in the 80s so I knew how good games could be and how incredibly shitty, barely recognizable, 2600 ports of games were. I always hated those f*cking sticks. They required so much damned muscle to use!
When the NES came out I was impressed with Super Mario Bros and the NES ports of Donkey Kong 3, Donkey Kong Junior, etc. Of course, once the NES really got going it too started to be flooded with horrendous ports of shit way beyond its grasp like Ikari Warriors, Heavy Barrel, and whatever the hell those Strider, Rygar and Ninja Gaiden things were supposed to be. Putting shops in a game does not make up for its shortcomings!
My favorite NES games have always been the ones it handled easily like Excitebike and Ballon Fight. By the time stuff like Battletoads and Mighty Final Fight came out the flicker and slowdown were so damned terrible...
Similarly, Combat, the 2600 pack-in is my favorite 2600 game with Warlords close behind. Rampage and Double Dragon are very nearly unplayable to anyone who has actually experienced a decent video game in their life. Pac Man isn't any use to a real fan of the arcade game, but it serves more like a Pac Man from a parallel universe. If you've never been to the arcade Pac Man 2600 is a decent game. If you spent $200 at the arcade on the real thing you are going to be pretty pissed with the POS 2600 game.
One of the ways I describe PC Engine is that its basically NES without the flicker. 8-bit games done properly. Its not just because the system is way more powerful than a NES, but also because usually the developers knew how to chill the f*ck out. Instead of flickering all over the place, just make the sprites a little smaller or don't layer them so much.