Pros and cons to revolvers and pistols:
Revolvers:
- simple
- hardly ever a failure to fire (no jams, etc)
- limited number of rounds
- heavier trigger pull usually
- easy to clean/break down
Semi-Autos
- more complex
- is more likely to have a failure to fire, failure to eject, etc. (however, I've yet to have one in any of my Glocks. I have had a couple in a few Sigs due to it not racking properly)
- many more rounds in most models than a revolver
- less of a trigger pull compared to most revolvers
- much more complex to clean/break down
When I've taken these things into consideration, I've opted mainly for a semi-auto pistol. They are very reliable now-a-days and I don't mind the break down. I like the extra rounds carried, and if you get a polymer pistol, they are much lighter in weight.
However, it will always become a personal preference. Good luck in your decision.