The best performance of 5th I've ever heard is by Evgeny Svetlanov / USSR Symphony Orch. that I have on an old Melodiya LP. Some of the best stuff came off those LPs (like Franck's D-minor symphony, Saint-Saens 3rd, Tchaikovsky's 4-6 by Fedoseyev, ah, those were the times).
Of many CDs I've tried in recent years, Gardiner was (to me) the best. Karajan is also good and a great value since the complete 1963 cycle was being sold for CDN$30 for quite a few years now. The first movement of 9th was a really great performance on that set. I have Cleiber's 5/7 - now also available on SACD for those who want it - and I was satisfied but not blown away. It was a while ago though, I have better equipment now so maybe I should revisit it. Oh, I also got a cheap Kurt Masur's NY performance, that wasn't bad either (at least sonically).
I didn't like Abbado's 2000, except for the 8th Symphony which was very nice. Sonically DG didn't seem that good on that set.