NES. Got one in '93, a market trader who had a video games stall that I used to visit regularly had a complete, boxed PAL NES system (complete with SMB3) and I had Ecco The Dolphin and Two Crude Dudes on PAL Megadrive, and basically in trade-in value I got a straight swap, with £2 extra on my behalf, so got a battered, boxless Excitebike cart along for the ride.
I remember buiding up quite a hefty collection of 40+NES games, most of the Megamans, Mission: Impossible, Gradius, Trojan, Snake, Rattle And Roll and Solstice, Maniac Mansion, even the Action 52 cartridge, loads.
I just had this system that had games that looked like slightly more defined C64 games, but had worse scrolling and sound (music, especially). The only game I truly liked was Maniac Mansion. I *hated* the NES, and still can't gel with it.
I offloaded my NES with about 35 (mainly boxed) games for £70 in mid-1994, eight months later, and spent the cash I got on rap CDs I can now easily download for free!