If you can only get to the gym 2/3 times a week, i'd reccomend a simple push/pull split.
Push one day, pull the next. Just alternate it everytime you go into the gym.
Push Day;
Bench press 4 sets of 8
Shoulder press 4 sets of 8
Sqauts 4 sets of 8
Incline Press 4 sets of 8
Tricep cable pushdowns 4 sets of 8
Pull Day;
Deadlifts 6 sets of 6
Seated cable row 4 sets of 8
Single Arm Dumbell Row 4 sets of 8
Bicep Curls 4 sets of 8
Bent over barbell rows (double underhand) 4 sets of 8
Just made that up off the top of my head, never done it but it more or less hits everything. If you google push/pull routine i expect there will be loads more, maybe better programmes.
That said, with that infrequent/un-structured time in the gym i don't think any plan is going to hit every muscle enough (not putting you down, i understand you have other commitments!) so rather than doing shoulders one day then arms then back etc... and hitting every muscle once every 2 weeks, this way you get a bit done all over every week.
Just my input, that's what i'd do in your position.
Good luck.