2.5GB in my PowerMac G5 (upgrading to 4GB soon)
2.0GB in my MacBook Pro (upgrading to 3GB once prices are resonable)
512 in MacBook (2GB once I have the money)
I have 2 GB of ram in my Mac Pro. It's great for everything except when I do some Shake and Final Cut, it hits the 2 GB wall but it's still very fast so I'll wait. I bought it with 2 GB because I think it's a minimum for video editing and I thought that I will add more in the future. I hope the price of 2x2GB will go down within the next year. I am kind of hoping it goes down from $1000 CAD to about $500 CAD. That would convince me to upgrade up to 6 GB!!!
Depending on which computer I use, it varies between 2k and 1 gig.
I'll be getting a Mac Mini maxed out at 2 gigs, but for now, I'm in between computers a lot.
I'm still using the stock 512MB, and honestly it's fine for me. Of course the 1GB upgrade would be nice, but I'd rather put the money towards a new macbook.