Excellent thread! Lovely to see some BMXers out there, had a Rebel Racing 'General Lee' I bought for a pittance off some lads round the way who were sponsored BMX riders so had loads of bikes. It got nicked in the 90s sadly as they're pretty rare as I understand. Rather like this one.
SW always my fave but other 3 were..
Lego - the 80s space stuff was awesome. Still got a bag of it and found this site with a massive library of instructions, would be great fun to rebuild them back to thier original sets- http://www.peeron.com/scans/
Scaletrix - didn't have one by my mate's set-up was sweet, just lots of basic track parts, loved building new monster tracks and racing for hours.
MOTU - my brother still has his collection which I reckon is about 80% of the figures released approx. Castle Greyskull was awesomely massive and sometimes made a gruesome hangout for my Imperials!
Commodore 64 was the end of my collecting days but me and my brother would pick up various bits from jumble sales so there's some Transformers, Ghostbusters, Thundercats odds and ends about. Had a Subbuteo set which we played for ages, as was a friends terrific Catapault game.
For retro laughs try this from Wales' premier Hip-hop crew Goldie Lookin' Chain, all about being a kid in 1983. It even mentions collecting SW figures (around 2:10). I should probably warn that it's not suitable for young ears, due the mighty GLC being a bit potty mouthed. Fresh!
http://www.youtube.com/watch?v=wzVpEOV3Qfk