I played 1 and 2 a TON...for years. Played the new one for a few months but never really got into it as much. I think it's because they were still working on patches and some of the gameplay was broken when it first released (people not coming and leaving the park correctly, screwed up ratings on people's ride prefs, bugs in staff that quit working, etc.)
People were making some awesome stuff though. I made a couple coasters that were pretty cool, I thought. Post some screens of anything cool you design.