I used to do a 4 day program when I was trying to bulk up and get ready for rugby.
It consisted of Legs, Chest, Shoulders/Back, and Core/Cardio.
Day 1:
15 minute spin on bike.
5x5 Clean and Jerk
5x5 Squats (bar)
5x5 Weighted Walking Lunges
Then if I still wasn't tired I'd flip a bosu ball upside down, grab a medicine ball, and do front squats on the bosu ball with the medicine ball in front of me until I couldn't do anymore.
Day 2:
10 minute spin on bike.
5x5 Decline bench
5x5 Dumbbell bench
5x5 Incline bench
5x5 Dumbbell pec-fly
4 Sets of push-ups to failure
Day 3 really varied. It usually had super-sets of rows, upright rows, pullups, lat-pulldowns, shoulder-press and military press. Sometimes I did some extra chest and core on day 3 but I'd really just sort of wing it.
Day 4:
1 hour run, with a break after 15 minutes to stretch.
30 minutes of very tough abs and core workout. We did as a group some days, so everyone would try to act all tough by pitching hard core-workouts to the whole group. We'd all be sore as hell by the end of it.
No rest days. Just straight back to day 1 after day 4 was finished. I managed to gain 15 pounds of muscle through this method, but I was taking in like 6000-8500 calories a day through 9 meals.
Now I just bike hard for an hour every day and work. I kinda wanna cut some fat and get a 6-pack to show through. It's not as cool as being huge, but I'll work out seriously again once school starts back up.