Buoyed by the penultimate episode of Friends and a rockin' turnout for its cheesy quake saga 10.5, NBC won the ratings race last week among total viewers and adults aged 18-49. The Peacock also benefited from the one-hour season finale of Will & Grace, which drew 20.5 million viewers its biggest audience in more than a year. CBS ranked a strong second among viewers, thanks to another No. 1. finish from CSI. Rounding out the top five: Friends, American Idol (Tues.), American Idol (Wed.) and ER.