Sedra/Smith was a classic - I remember I picked mine up used from the campus bookstore, and it'd been cycled through the course so many times it was almost perfectly annotated and highlighted for the way one particular prof taught the material.
Of all the textbooks I used in my schooling, Sedra & Smith is on the short list of ones I remember explicitly - along with Silberschatz & Galvin on operating systems (with the ridiculous dinosaurs on the cover), Oppenheim and Willsky's Signals and Systems, EOPL, and Stewart's Calculus.
I also had the Silberschatz (such a weird cover!) and Oppenheim books. I think Sedra and Smith is pretty widely accepted as the canonical introductory electronics book.
Most frustrating book I had to deal with: Random Variables and Stochastic Processes by Papoulis and Pillai. I understand it's also very popular, but I found it really hard to follow.
Of all the textbooks I used in my schooling, Sedra & Smith is on the short list of ones I remember explicitly - along with Silberschatz & Galvin on operating systems (with the ridiculous dinosaurs on the cover), Oppenheim and Willsky's Signals and Systems, EOPL, and Stewart's Calculus.