I am a hardcore sci-fi fan. Although I basically grew up in a library, the most fascinating part of it were the two or three racks nobody frequented than me: the racks were full of hardcore sci-fi like heinlein, asimov, pkdick, silverberg, leguin, pohl, you name them. In that sense, Sci-Fi is actually dying, because in the last 10 years, I hardly found something that even remotely compares with the great work of thes…
and really quite enjoyed http://en.wikipedia.org/wiki/The_Nights_Dawn_Trilogy
and found pretty much everything in http://en.wikipedia.org/wiki/Revelation_Space_universe to be as good as anything I've read by Heinlein, Clark et al.
Honestly, there's tons of good stuff out there, but it's just hard to separate it from the pulp. With the oldie goldies it's relatively easy because we have a few decades of people assessing those books.