24 and I had a few because a lot of them were being sold cheaply in car boot sales (similar to yard sales but in a field where everyone brings their crap and sells it literally out of their car boot). I had a little yellow thing that played Pac Man by using a system of LEDs to light up the symbols instead of using an actual screen. I had a SEGA Master System, an NES, another little LED rip-off thing that played the original Donkey Kong game and last but not least.
One of these bad boys.
EDIT: Off topic, but out of curiosity, did anyone else in the U.K. find it difficult to get games for the NES? I had loads for the Master System and the Mega Drive II, but barely any for the NES. I remember getting Ninja Gaiden, Castlevania and the original Ultima (which I never completed) and some racing game I can't remember the name of, but not much else.