Well the pension scheme I am in (local government) is probably the best scheme type (benefit wise) that you could be in and mine will return me (bearing in mind that I complete 40yrs service) 50% of my final salary (index linked) on retirement until I die, together with a lump sum payment that is in the region of 2 x your salary on retirement tax free (I think it's 2 times or is it 1... cant remember).
So for normal pensions you could probably devide that by 4 to get a figure!
TBH If I retired now on a full pension I could comfortably live (based on present salary)

So hopefully I wont have anything to worry about when I'm 65..... saying that though I will probably die at 66