Let's see:

12 sets of bibs
20 or so s/s jerseys
5 l/s jerseys
3 sets of armwarmers
2 sets of kneewarmerrs
1 pair of roubaix knickers (really need another pair--they're super for spring and fall)
6 windvests
2 jackets
1 skull cap
5 cycling caps
I don't know how many pairs of gloves.

Now, I don't suggest you run out and buy all this stuff. I accumulated it over many years of riding, and as I race and each year I get at least 2 jerseys and 2 bibs, they tend to pile up. I save my current year kit for races and the big local group rides, but use the older stuff for commuting and solo training. 3 sets is plenty for commuting.