If you can't make a 3 day routine at least 3 out of 4 weeks you should go full body 2 times per week with an optional 3rd day.
Cycle each group, for instance a group for day one would be bench, row, squat, bench, row, squat, bench, row, squat. The point of doing the workout in groups is to reduce the recovery time needed between sets so you can get in and out of the gym fast. This routine can be done in 30 minutes if you push yourself (if you're not winded you're not working hard enough) It typically will take about 45 minutes because the squats tend to slow people down.
Day one:
Group 1
Flat Bench 3 sets 8-10 reps.
Seated row 3 sets 8-10 reps
Squat 3 sets 8-10 reps
Group 2
Shoulder press 3 sets 8-10 reps
Lat pull down 3 sets 8-10 reps
Leg Press 3 sets 8-10 reps
Group 3
Dips 3 sets (to failure)
Upright Rows 3 sets 8-10 reps
Calf raises 3 sets 8-10 reps
Hanging leg raises 3 sets (to failure)
Day 2
Group 1
Incline Bench Dumbells 3 sets 8-10 reps
Bent over rows 3 sets 8-10 reps
Squat 3 sets 8-10 reps
Group 2
Dumbell Shoulder press 3 sets 8-10 reps
Pull ups 3 sets (to failure)
Leg Press 3 sets 8-10 reps
Group 3
Skull crushers 3 sets 8-10 reps
Barbell bicep curls 3 sets 8-10 reps
Calf raises 3 sets 8-10 reps
Ab crunches 3 sets (to failure)
