I would say if you can go out and try pedals, do it. Everyone has different opinions, and while reputation and advice from knowledgeable people will get you most of the way, sometimes you just have to use your own ears.
As for me I have a danelectro Daddy-O overdrive, a lot of people don't like it, but I do like some of the sounds it has.
I would say there are some good guidelines to follow.
1. If you are able to go and test the pedals, use a guitar that resembles your own in quality and style, as it has been said many times, if you go and play a PRS or Gibson, the guitar is going to make anything you try sound better. So use a guitar that is like your own.
2. Try different brands of the same type of effect, that way you will have a sounding board.
3. If its made of plastic, or costs less than 50$ its probably crap.
4. Boss, Jim Dunlop, MXR, Digitech, Ernie Ball, Morley, and Vox all get my stamp of approval(for what its worth, hah!

)
5. Let your ears tell you what sounds good, not a name tag, price tag, or salesman.
Oh and good luck and happy hunting.