Arguably the biggest name from that 99 tournment was Landon Donovan based on world profile.
I'd say Adriano because of his status in Brazil, rest of South America and Europe.
The South Americans tend not to rate US players.
Donovan only had brief stints with Everton in the MLS off-seasons, otherwise his games in MLS attracted not so much international attention.
In contrast Adriano played 48 times for Brazil's senior team (27 goals) where he won the Copa America and Confeds Cup , as well as Inter Milan (123 games) where he won Serie A four times and the Italian cup twice.
- Copa América: 2004 – Golden Ball for The Best Player of the Tournament and Golden Shoe for Top Scorer
- Confederations Cup: 2005 – Golden Ball for The Best Player of the Tournament and Golden Shoe for Top Scorer
Adriano was also top-scorer and best player in Brazil's national championship twice (and won two titles).
Adriano started in two of Brazil's group games at World Cup 2006, in the round of 16 and came on as a sub in the quarter-final loss to France. He played in qualifiers for World Cup 2010 but missed the final squad.