I'm not really partial to one or the other. However, I'll take any opportunity to tell this story.
I have always wanted a 1969 Blazer because that's what year I was born, but when I got to looking seriously, I saw a 1st gen Jimmy with the quad headlights and I really liked that look better.
I have owned 1 Blazer, a 1977 model. Other than that, I have owned a 1979 GMC long bed 4x4, a 2000 Jimmy 4-door 4x4 (the mid size version, which I still have), a 1995 Jimmy 4x2 2-door (another mid size), and a 1970 Jimmy that I have had for almost a year now. I haven't had a chance to do any off roading in my '70 yet, but I hope to soon!
I have really liked every one of them, and it sucked when I had to get rid of the ones I no longer have. My favorite would be the '70 if it didn't have so much rust.