For wild camping I'm using the Snugpak Jungle bag in summer and the UK army/Fesca Medium weight bag with polycotton liner in the Winter. I have to say the new army 'medium' bag is probably the best military bag I've ever used. So warm. The only downside is the bulk and weight, and the liner is a bit of a faff. I managed to get the Medium bag (large), liner and MTP MVP bivibag new as part of a deal on ebay for £70.
I can boost the Jungle bag using either a US poncho liner or a fleece throw that we have.
When I'm hammocking the Snugpak underblanket does the trick with the sleeping bag appropriate to the temps.
For family camping I have a pair of Vango Nitestar 250's - the left hand and right hand zip style, so me and the missus can keep each other warm, so to speak.
I still have a Snugpak Discovery bag from the 90's that I bought to take to the alps. Was a great sleeping bag, just a shame it was a pinky red colour.
I've bought the boy a 'medium' bag too for when he gets his **** into Winter camping. He has a Vango Lunar 250 for the time being.
Will probably get the boy the army Lightweight bag next year if he shows an interest in coming along with me when I go hammocking.