I have had boxers all my life... Have one now, 11 years old. It's really a great family dog, can be trained as a watchdog also, lots of energy and stamina, they are not at all aggressive as some people think, great with children... I'd always go for a boxer, for me they are perfect.
The problem with them is that they are very sensitive, can have problems with their skin, heart, spine, maybe the worse is with their gums... My dog has that, the meat is growing over his teeth and we're at the vet's almost every week...
Epilepsy is also a big problem with this breed, and a relative short lifetime, from 8-10 years, but I know one that died at the age of 7 because of a heart attack. We were on a field where we take our dogs to play, he was running one moment and the next he was lying dead... He never showed any signs..