I warmly endorse the GP100. I own a 4" stainless model and have a fair amount of experience shooting a 6" stainless one.
Rugged. It's a pleasure to own a gun that you can feed any factory .357 load in any amount you like without worrying about wear.
Reliable. I had a little cylinder binding until I learned to clean the face of the cylinder properly. Since then, c. 1500 rounds without a problem.
Accurate. This is an underappreciated attribute of the GP. Everyone knows Rugers are tough, but my 4" GP is a great shooter too. Shames my S&W Model 19.
The trigger improves. This often-stated trait of the GP100 isn't just whitewash. After about 500 rounds and some dryfiring, the improvement was evident. I now have no complaints about my GP's smooth, even, mediumweight double action trigger. It's not a Python trigger, but it's good. Ditto for the SA trigger.