Well I started watching F1 in the late ninties and onwards, on a fair few occasions we saw Schumacher beach his car which always provided excitement.
I am not a fan of huge run offs, drivers can miss the chicane and comeback on and keep the position, best example Hulkenberg at Monza 2010, he did it several times there. Tarmac also makes the track look ugly, Silverstone used to be full of gravel, now it's all tarmac. I think gravel provides more excitement, cars going off, or cars trying to avoid going off after a mistake. Tarmac has it's benefits aswell...
I would say both tarmac and gravel, Malaysia seems to have this, Massa 2008 going off, it was half tarmac then near the tyre wall there was gravel, it was enough to put him out of the race. A bit of tarmac and a bit of gravel in corners like those, chicanes should just have gravel, high speed corners tarmac/gravel, slow speed corners.