I actually created a list when I was raising capital for my startup. Hope it is of use, I visited at least 1/2 of them so happy to give any directions on how to approach them.

http://blog.tareasplus.com/100-fondos-de-capital-de-riesgo-en-silicon-valley/

Happy to jump on a call :)

Mattermark is doing a realtime graph of this that seems to update daily with the most active investments of that day and the size of the investment.

http://mattermark.com/app/Benchmarking

Pitchbook and prequin are some of the few sources for returns data which shows how financially successful a firm is. For anonymous ratings check out thefunded.

Directly asking entrepreneurs whether they liked their VCs is probably the best way. If certain names keep coming up as great then those are likely the folks worth speaking with. Of course certain firms are thought of as tier 1 and legends in the industry, but that doesn't mean they are right as partners for you.