This list and order is based on their lead guitar work/songwriting contributions(licks,riffs,whatnot to megadeth)
1. Marty Friedman
2. Al Pitrelli
3. Chris Poland
4. Chris Broderick
2 and 3 may be interchangable but don't you just love dread and the fugitive mind? it sounds old school heavy metal but at the same time sounds modern haha labo!