Go to click here and this will list all of the channels available on Freeview - download the pdf file near the top of page 1.
However some restrictions apply as you will only get all of these if your are tuned to a main transmitter, many of the relays that people have to use only supply a sub-set of these. If you are in Wales you will get a different line up to account for S4C etc. So it can be complex.
Indeed if you have recently suffered DSO then it's probable that some of the new multiplex's won't be on full power for some considerable time (2012 when the last analogue transmitter is finally switched off) because of interference between analogue and digital signals on adjacent transmitters.
Personally I'd go to Factory Reset then do a completely new Channel Tune. It might even pay to manually tune the channels to avoid cross interference if that's the problem.
I have both satellite and terrestrial digital and terrestrial cause more problems more of the time.