If you thought sphere was tedious, what'd you think of Andromeda Strain?  
That's another one I loved, but will admit that it was a bit slow-moving.  I put sphere above it for the reason that it wasn't, in my mind at least, tedious at all.  Would have made a great sci-fi thriller/thinker if someone like Spielberg or Cameron had done it.  
Who's Follet?