My family is getting my much younger brother a netbook for Christmas, and I'm picking it out. The sweet spot as far as prices go is 1 GB of RAM, but I'm worried that it's not enough for what he does: youtube + flash games.
Personally I feel 1GB of RAM is not enough. Even for the lightest use on a computer, any modern operating system (read: Windows XP, Vista, 7) will need more than that if you're planning on opening more than one tab in a browser and having a PDF or word document open at the same time.
I would recommend going with a minimum of 2GB of RAM. Keep in mind that smartphones are starting to ship with 512 or even 1GB of RAM where multitasking is still somewhat limited as is app-size, etc.
I would recommend 2GB, but to be honest 1GB would probably be fine and upgrading to 2GB in the future wouldn't be that difficult. If he isn't doing youtube and flash games at the same time I'm guessing that 1GB would be just fine. Windows 7 does a rather nice job of memory management and so long as there isn't a lot of other applications starting with Windows or running in the background then it should be okay.