They're both icons. And Michael Jackson respected Elvis, sorry MJ fans, your idol doesn't approve of your insulting Elvis.
Anyway, it depends on what you mean, better as in a personal opinion of based on records sales ect?
Is in four Hall of Fames ( Rockabilly, Country, Gospel and Rock N'Roll)
Has had more 100 top billboard hits ( at 108) then anyone else.
Has had more top 40 billboard hits then anyone else.
Has had one of the most #1 hits on the Billboards top 100 ( 17 - 18)
Has sold more then 1 billion records ( the higher estimates are at 1.4)
Received 3 Grammies and the Lifetime achievement award.
Is credited with the 1st music video 'Jailhouse Rock.'
His "Aloha from Hawaii" special was the most watched in TV history by a solo artist.
Michael Jackson Feats:
Revolutionized the music video world.
Inducted into the Dancers Hall of Fame and the Rock N' Roll Hall of Fame ... TWICE. He was also inducted both the Vocalist Hall of Fame and the Songwritters Hall of Fame.
Sold over 750 million records.
Thriller, his album, has sold more then any other single album. It has sales of over 100 million.
Recieved 13 grammies and the Legend and Lifetime Achievement awards.
Recieved the World's Music Award
Recieved 'America's Music Award also.'
Both Elvis and Michael Jackson were generous. Both donated sums to money. Both were accused of lies ( Elvis was claimed to be racist and a thief ... he was neither. His racial slur never happened as he wasn't in the area of Boston when he was 'interviewed.' He also has creditted African Americans as being his inspiration for music. MJ also never molasted children. The court was full of BS.)
But, to answer your plain question, Elvis Presley. He acutally new several insturments ( you said musician, not singer-songwritter, the latter would be an MJ victory by far.) unlike Michael Jackson.
Me, Elvis on wiki, MJ on wiki.