Well I am a BASC member and very happy with them. Just attended a range day at Bisley (last week) and had
a) a great day shooting a rifle provided by BASC, and
b) completed an assessment which should entitle me to shoot on MOD ranges
The latter may not be important to many of you, but for me, I am just trying to get established with stalking and shooting as a hobby/pastime, and I don't have a lot of land, and the only ranges in the South East where you can shoot full bore seem to be MOD ones which require certification - so being a member of BASC allowed me to go ahead and get range certified without having to attempt to join a local target shooting club.
It has also helped me get shooting permissions for rabbits/small game.
I know that other organisations would also provide cover, and maybe for a little less, and I don't find the magazine all that useful - too much of it is about pheasant rearing for my taste, BUT BASC is essentially a union for recreational shooting of all types, and I feel that the subs are well worth it - for the insurance, for all the advice on the website, for the training opportunities that they offer.
I have paid a lot more for things I have used a lot less!