Cabo San Lucas is located on the very tip of the Baja Peninsula and between this peninsula and Mexico's mainland is the Sea of Cortez. You have only 5% chance of a cloudy day so the weather is sure to please! You also feel very welcome and safe and could even drink the water right out of the tap at our resort (which came in handy with 3am cottonmouth resulting from too much tequila).
It isn't a cheap place to go, but not completely unreasonable either. The downtown isn't very large which makes it so nice because you know exactly where to go for great nightlife... Cabo Wabo! We also went to Gigglin' Marlin and had a great time as well. This is where they will string you up by your ankles and give you a tequila shot!
Cabo is a GREAT place to go offshore fishing. It takes no time at all to get to deep water and it is very reasonably priced. There was a blue and black marlin fishing tournament going on right before we got there and we had a blue on our line!... until the line snapped :(
I got to see a seal swimming by the harbor, baby sea turtles let go into the ocean, hummingbirds, giant moths, and a ton of fish, so the wildlife is abundant. If I went back I think I would want to go on a snorkel excursion in the sea of cortez. My husband and I spent excursion money on a couple's massage this time. ;)
All in all, it was a great way to see Mexico as an "adult" (I went to Cancun when I was 18, and that is the best choice for that age I am guessing! haha). I love seeing different places so I don't know if I would go back or not, but I would recommend it to anyone looking for a getaway completely different from where they live, but not too far away and not too much of a hassle.