The answer somewhat depends on the version of the V2500 you are operating. I have experience with two variants of the V2500. The V2500-A1 is the older version of the engine, and it has had some problems with compressor blade failures due to something called "rotor bow". If you do some googling, you can probably find more info on the phenomena and on what they tried to do to fix it. The -A1 could also be purchased with a Thrust Bump option, which essentially gives you a thrust boost (approx 10%) for takeoff when the RTOW requires it. This adds significantly to the wear and tear and as a result, these engines fell out of favour with most airlines. The second version I've flown (V2527-A5) is a much better engine with more power and greater reliability but it doe sburn more fuel than it's cousin.
The CFM56 is a very reliable engine. There are over 16,000 of them in operation world wide on various types including all B737-NGs, which is a testament to their durability and longevity. My company has been operating them for 10 years and we just recently had our first engine failure due to an internal problem, the cause of which is yet to be determined. Personally, I would take a CFM engine any day over either version of the V2500.