Hi, survey done.
The subscription sites I use are Ancestry (World sub) and Findmypast (UK sub). Personally I prefer Ancestry, it is the first site I subscribed to as a novice (almost 10 years ago) and I found it quite easy to navigate.
I have a couple of gripes though about Ancestry. Firstly, those annoying hints which often throw up results which are clearly not my ancestors - a novice could easily accept these suggestions and follow the wrong family line. Another is the assumption that you are in America. As far as I know there are 15 towns in the world called Birmingham, 14 in America, 1 in the UK. Many of my Ancestors are from Birmingham, England, so to ensure I get the best results I have had to go through my Ancestry online tree and make sure I have stated England on every record.
Although I don't find Findmypast as easy to navigate, I subscribe mainly for the 1939 Register (which does have some problems with transcription errors) and the Newspaper records.