Fleischer (sp? Hah, I should be able to spell that confidently...), most probably. His Beethoven concerto recordings are, of course, practically untouchable. But then again I haven't heard too many other recordings.
Next to the 3rd concerto, the 5th is probably my least favourite, but keep in mind I'm not very much a fan of Beethoven (no matter HOW great he was, and he definitely was one of the best ever) and in particular don't care much for his later works, which start the transition into the Romantic era. I mean, I like them somewhat, but they certainly aren't my favourite pieces, and definitely not my favourite from Beethoven. I much prefer the Classical elegance of the 2nd concerto--tops on my list--and the light-hearted comedy and charming nature of the 1st, compared to the somewhat empty virtuosity of the 5th concerto. Sure, you can say that since I'm something of a Lisztian myself, but nevertheless Beethoven's brand of virtuosity, or even better yet, the actual melodies, just don't appeal to me (maybe I'm just too shallow, and like Liszt more than Beethoven because of it! I don't know! Say what you will, it doesn't matter..)
I will say that I like the 2nd movement quite a bit, though it does seem a little out of place with the rest of the concerto. It's almost Chopin-y....sort of...
And also, I enjoy the 4th concerto a little bit more than the 5th and 3rd. I recognise the 4th as possibly his best concerto from a compositional and overal musical viewpoint, but I can't really make any claims beyond that since I am no true scholar and can't really analyse music beyond what I hear and how I like it. From that, more simplistic take on it, I have to say I personally prefer the first two. Though at one time, a few years ago, I did consider learning the 5th for a competition (my teacher thought I had gone insane and instead shoved the 2nd Beethoven, Grieg, and Schumann concerti at me, none of which interested me at the time, sadly).
And get the box of Fleischer CDs! It's really monumental, a legendary recording from just a few years before his accident with the Brahms concerto. I think Kuerti also has a set out, which has to be well worth it considering he's such a good Beethoven player. I saw him do the 3rd a year or two ago...and, on a side note, I also saw Richard Goode play the 4th MANY years ago. Excellent performances.
One should either be a work of art, or wear a work of art.
You know, some people just have natural talents-like some people play the piano but aren't very tall.