I personally have never paid much attention to the brand of lights I buy (normally whatever is on sale or inexpensive). When it comes to the tree, I think you are only dealing with two types of string lights .. multicolored or simple white. I am a fan of white lights (paired with brightly colored ornaments)</i> but everyone has their own tastes.
If you plan to decorate the exterior of your house, of course make sure you use out-door lights, but I would say away from the *new* Solar powered Christmas Lights. I tried them last year and wasn't too happy with them, they save you on the electric bill but they never really get as "bright" as tradition plug lights. For lack of a better word they were Dull. Everyone on my street puts lights on the house, so it was a row of brightly colored homes and then my 'dull' lighting. I ended up having to go back out and buy normal out-door lights.
Someone else may have had a different experience though.
"I have always thought of Christmas time, when it has come round, as a good time; a kind, forgiving, charitable time; the only time I know of, in the long calendar of the year, when men and women seem by one consent to open their shut-up hearts freely, and to think of people below them as if they really were fellow passengers to the grave, and not another race of creatures bound on other journeys." ~Charles Dickens