The Black Entertainment Network "made me who I am today," Brown told the Shrine Auditorium audience.
Said the dapper Prince: "This was unexpected; I appreciate it nonetheless."
Oscar-winner Jamie Foxx entered the show as the top nominee with five bids for BET Awards, which recognize the best in hip-hop, R&B, gospel and music videos, as well as athletes and actors.
Damon Wayans told The Associated Press before the live broadcast that he was excited about hosting the event.
"It's going to be a big, black blast," he said. "Even if you're not nominated, you're there and you want a front-row seat."
Special honors planned for the evening included a lifetime achievement award for Chaka Khan and a humanitarian award for Harry Belafonte.
"It means a great deal to be recognized by your people for your body of work," Khan told The AP. "I've been doing this a long time, so it's a beautiful thing. I'm honored."
Khan was among a star-studded roster of performers, which included Beyonce, Prince, Mariah Carey, Kanye West, four-time nominee Mary J. Blige, and Foxx, who had five nominations.
Elliott and Busta Rhymes also were multiple nominees, with four nods each. Brown, West, and rapper Ne-Yo each had three nominations.
Both Foxx and Chris "Ludacris" Bridges were nominated in musical and acting categories.
The Black Entertainment Network's 2005 Awards was the most-watched program in the network's 26-year history, executives said. Reginald Hudlin, BET president of entertainment, called it "the best awards show on television, period. No qualifier."
Wayans said he prepared for his hosting role by doing standup comedy and planned to improvise his material.
"I'd probably forget my lines" if they were scripted, he said.
BET Award winners were decided by a panel of executives from entertainment companies, record labels and the media, except the Viewers' Choice award, which fans voted for online.