Dadgum man, take it easy on the caffeine!! Actually, lately I have been drinking quite a bit of caffeine, at least for me. A coke or 2, plus a coffee, all after 5 pm...and when I take Excedrin, which has twice as much caffeine as coffee, then I'm wired.
I used to drink 3 of Monster blues a day, sometimes 4. My job requires alot of thought throughout the day so the stimulant helps to stay sharp. Plus it has a ton of B vitamins which really help mental capacity.
Very low sugar so it's better than sucking down sodas, just a bit pricey.
The caffeine contained in a soda does nothing for me. I'm too resistant to it. I've found that it takes about 2 - 3 weeks to lower your tolerance to caffeine, and about 2 days to recoup it.
Coffee is the most caffeine dense beverage by far. Two 8 oz. cups has alot of caffeine in it, well more than 32 oz. of Monster.