I defintely recommend Tea Tree Oil!
It can be bought at any health store, and most grocery stores/drug stores.
Even though it's an oil, it doesn't make your skin oily.
The way I use it is every night before bed, put 3-4 drops on a Q-tip, and ONLY put it on the blemishes/pimples (We all know how men use waayy too much of everything :P).
Do not use it on your whole face as it will dry your skin out like crazy, but since you're only putting a dab on the problem area, it will zap the zit in no time.
Even those really stubborn zits go away in 3-5 days with Tea Tree Oil.
The best part of Tea Tree Oil is that since you're using such a small amount, it will literally last months! I've had my bottle for half a year now!