I can second what's been said about Navfree, for free it's excellent.
One thing to note, it used to have post code search, and that disappeared on the last update.
There was an update to it yesterday which I think brings post code search facility back, but haven't downloaded it to test yet.
A feature I often use is the google search within the app - a quick and easy way of finding places if you don't know the address fully eg pubs, hospitals (in that order generally)