According to a book I'm reading by Tudor Bompa and Michael Carrera,

If you believe that EMG tests hold water, the following results may help you in your quest....


Quadriceps (rectus femoris):-

Safety squats (90 degree)-----88
Seated leg extensions---(toes straight)----86
Half squats--(90 degree angle)---78
Leg Press---(110 degeree angle)--76
Smith machine squats---(90 degree angle)--60

Hamstrings (biceps femoris)

Standing leg curls----82
Lying leg curls---71
Seated leg curls ---58
Modified hamstring deadlifts---56

Hamstrings (semitendinosus)

Seated leg curls-----88
Standing leg curls----79
Lying leg curls----70
Modified hamstring deadlifts----63

Calf Muscle (gastrocnemius)

Donkey calf raises----80
Standing one-leg calf raise----79
Standing 2 leg calf raise----68
Seated calf raise----61

Triceps (outer haed)

Decline triceps extension------92
Triceps pressdown (angled bar).....90
Tricep dip between benches-----87
One-arm cable triceps ext.--(rev grip)---85
Overhead rope triceps ext. ----84
Seated one-arm DB triceps ext.---(neutral grip)--82
Narrow-grip bench press----72

Lats (latissimus dorsi)

Bent-over Barbell Rows----93
One-arm Dumbell Rows---(alternating)--91
T-bar rows-----89
Lat pulldowns to the front----86
Seated pulley rows------83

Biceps Long Head (biceps brachii)

Preacher curls----90
Incline seated Dumbell curls (alternating)----88
Standing bicep barbell curl----86
Standing Dumbell curls (alternating)---84
Concentration DB curls----80
Standing Barbell curl (widegrip)----63
Standing E-Z bar curls (widegrip)---61

Anterior Deltoids:-

Seated front dumbell Press-------79
Standing front dumbell raises----73
Seated front barbell press-----61

Medial Deltoids:-

Standing dumbell side laterals----57
Seated dumbell side laterals----53
cable side laterals-----49


Posterior deltoifds:-

Standing dumbell bent laterals----85
Seated dumbell bent laterals----83
Standing cable bent laterals----77

Pectoralis Major (Pecs):-

Decline Dumbell bench press-------93
Decline barbell bench press-----90
Pushups between benches----88
Flat dumbell bench press-----87
Flat Barbell bench press-----85
Flat Dumbell Flyes---------84

Pectoralis Minor (Upper pecs):-

Imcline Dumbell bench press------91
Incline barbell presses-----85
Incline Dumbell Flyes-----83
Incline Smith bench press----81