I typically show off Wii sports, Trauma Center or Warioware. if your friends are mature enough, they will stop with the kiddy games comment and enjoy those games for what they are: great games.
Sony PS3 120GB with Fedora Core 5 * Nintendo Wii * Sony PSP * Sony PS2 * 2x Sony KDSXBR1 R50 50 inch 1080p displays *
5x Dell P4 Optiplex GX280 * Dell Centrino Inspiron 600m * Dell dual Xeon Precision Workstation 690 * Mac Dual processor G5 * TabletKiosk EO
New Addition (2/28/2007): Dell Core Duo Inspiron XPS M1710
I know...young people tend to believe they are too mature and don't want to play "kiddie" games because they're embarrassed of what people may think of them and that's called being insecure of themselves..but as you grow up you begin to understand and being really mature and don't care if you're playing "kiddie" games anymore.