I remember the first time I got captivated by a unique timbre and momentum in Beethoven's orchestral sound was in a recording of The Emperor Concerto with Horst Stein and Freidrich Gulda. A name I'll never forget even if I did not encounter it again very much after the first time.
RIP
Daniel, all five Beethoven piano concertos with Gulda, the VPO and Horst Stein have been re-issued by Brilliant Classics, in their Piano Concertos set, their Piano Sonatas and Concertos set, and in the Complete Works sets (85 CD and 100 CD versions). I too was greatly taken by the recording of the 5th concerto on LP, then a bargain single CD issue (with the 4th), and now the 100 CD set.
Not too easy to get in the UK at the moment, so try
here for just the concertos.