If you're using the revolver for general recreational shooting it's your choice. For competition, check what is best for the sport. ICORE is heavy on 7 and 8 shot revolvers, IPSC gives less lattitude and IDPA is strict--6 shot with max 4" barrel.
If you are purchasing only one revolver I would go for either a 686 or M66 in 4" or Ruger/Taurus equivalent for versitility and being legal in all competition. That was my idea with the purchase of my first handgun, the 6" 686+, but I had not heard of IDPA at the time.
For home defense a 12 GA is superior, even Jerry (world's fastest DA revolver shooter) Miculek says so. If you insist on using a revolver in home defense use a cheap one as it will be taken as evidence, held indefinitely or forever and handled like trash. A 7 shot 686+, M66 or Ruger or Taurus equivalent are fine.
In relation to earlier comments about starting on the low cost end. I will have to say that as good as the PC 627 V-comp is and despite the extra beef and extra round of the 686+, my favorite is the M66 K-frame.
The M66 is only a six shot--my only "honest" revolver--but just pure fun to shoot. I don't worry about the fact that the 686+ is made to handle a steady diet of .375 magnum as my main uses are competition where .38 spl rules and marksmanship.