Jul 2009 for me, a little later than a few of ye olde timers. Decided I wanted to get into Oblivion mods, and this was the only site that got me to sign up.
It was the 4890 Roundup article that did it and I tried to find the 'Sapphire 4890 Atomic' highly praised in that review, but it feels like they only made them for reviewers given how scarce they were.
I do miss back when the site did a lot more than mostly GPUs and Cases. Speakers, RAM, SSDs, Mobos, etc. I'm sure the narrower focus is more profitable and there's not much point to RAM reviews most of the time anymore, but this place became my 'one stop shop' for info.
Being the only forum that is pretty strict on the the 'no religion, no politics' keeps the discussion a lot more civil which has probably been a big part in keeping me around.