I dont get it. Why do so many people love the 4th so much?! i mean its great and all and it represents the development of the piano concerto style but to me its just plain boring. Too much of it is just tune-less harmonic sequences and uninteresting arppegios as if Beethoven was struggling to change into the right key and trying to figure out what to do next. Theres not enough melodie. Ok the 2nd movement is gorgeous i must say, one of my favourite concerto slow movements actually. And he also has one great idea in the last movement, the main theme, which is fantastic. But there are no other good ideas for the rest of that movement, and after a while it gets very boring because he just keep recycling that same idea, making it sound like a set of variations.
Please don't get offended, those G major concerto fans out there. Nothing personal. I guess this is just one of the pieces that i will never learn. along with Rachmaninoff's 2nd concerto.

Way too overrated, i believe.
Oh and one more thing. I think Bb major concerto is the easiest. No. 1 is a great concerto, but its often overlooked. There are quite a few tricky bits in it. Its quite a daring concerto too and definitly ahead of its time. One of my favourites, as well as the C minor. Brilliant!