I'm a fan of six days a week training with moderate cardio.
I use to be that way. I usually make it to the gym 6 days a week now but the intensity is a little less. I have found over the years going to the gym M/W/F (and that is it) and using heavy weights is by far the best way to pack on solid muscle. I care less about that now and just enjoy working out.
M: tris and chest 30-45 mins of cardio + light abs
T: legs + bike for cardio 30 mins
W: back bis + 30-45 mins of cardio + light abs
TH: shoulders traps 30-45 mins of cardio
F: sometimes rest or do circuits with a focus on abs + cardio
Sat: weak area strengthening, i.e. lower back, rotator cuff and other body areas that have been plagued with injuries over the years. Adding this day and going in and doing the sissy exercisess has made a huge difference.
Cardio during the week consists of running or elliptical depending on how I feel. Keeping the joins free from overtraining is the main concern.
My schedule does vary from week to week though. I listen to my body and do not hesitate to skip the Wed workout and just move it to Thursday and skip the circuit training on Fridays etc.
My intensity has gone down quite a bit. The last hernia surgery keeps me in check. I no longer try to lift heavy weights and focus on higher reps and lower weights. Doing circuits is awesome too. I integrated that last Fall and it is an ass kicker.