Before flaming supercharged fanboys/girls start yelling at me, i have only seen matthew fox in Lost, We Are Marshall and Party of Five (with that ridiculous haircut), so am only basing off those performances.
Fox is a very capable actor, but often takes things too far, and finds a way to cry and raise his voice whenever possible. If he just turned down the volume knob a bit, he might get a seven from me.
His performances in 'Lost' are generally solid. he can express emotion well (but see above) and seems to interact smoothly with the other cast members.
So Matthew, stop crying, PLEASE?!