Neck through guitars:
I have owned a Gibson Firebird - neck through. A lot of sustain. LOL, made me sound good!
But FTW, you would find it hard to go past the Yamaha SG200 in production models. Loads of sustain, and they even have a brass plate put in for good measure. Pickups not too bad either, and the whole package is very playable (unlike the Firebird which is unbalanced - a bit of neck dive).