recommended versions of Beethoven symphonies?


anybody got any favorite versions of Beethoven symphonies?
I just got into the 9th and am floored by it's brilliance. I would like to become familiar with the better recordings of it and the others (the best performances as good as available sonically). I have a vinyl copy whose sonics are great and the orchestra seems excellent; but I'm new to these waters. It is a Japanese pressing from 1977; dennon "pcm recording" (mfg'd by Nippon Columbia co.). vaclav neumann conducting the czech philharmonic orchestra; prague philharmonic choir. I stumbled on this in mint condition for $6.00 and it blew me away (very intricate and subtle instumentation). so i went out and got all 9 in a set on cd: the Karajan 1963 versions, remastered 1997 on Deutsche Grammaphone. this seems to be recommended by some as "the best". I dunno about that but the 9th and the 1st (all i've heard so far) are certainly amazing! very powerful! quite different in places in approach from the vinyl 9th described above.
So: what else should I seek out?
Thanks very much for your thoughts.
tagyerit
The Karajan 6th sounds like he's in a rush to get to his next engagement. I suggest instead the Karl Boehm version with the Vienna Philharmonic. The Karajan 9th (1963) is the best I've heard so far.
I also like the Gardiner cycle. Period Orchestration and instruments. 20th century recordings are typically with larger orchestras which can obscure some of the subtle detail of this glorious music. The Gardiner cycle as a whole are very transparent with good overall performances and highly recommended.

Of course there are individual performances that stand out, One can never forget Bernstein's 7th at Tanglewood, one of my very favorites.
i wouldn't usually recommend this to someone new to beethoven, but as you appear to be venturing off into the HIP of beethoven (gardiner) i would suggest you give Harnoncourt's performances a listen. He doesn't restrict his instruments to period ones (horns) nor does he try to replicate the "original performance". all and all i find his work very enjoyable. it sounds a little closer to modern performances than gardiner or norrington but with a much leaner score(than in modern).
I do like the Harnoncourt a lot, it is one of the sets I got 2 weeks back. I also am enjoying the current Barenboim, another non period non historical performance (the playing is incredible and the recording very beautiful). also the Kleiber 5th (and 7th) on xrcd are great as suggested. Despite the fact that a lot of people remark that the Karajan is "heavy handed" or whatever, each time I come back to it and put it on it I am very happy to hear it (especially the ones I've found so far on vinyl). Furtwangler is...Furtwangler. like a rock, you can't argue with it. but on cd anyway the sound quality is so lacking that I gravitate to the other versions. (I don't have his live 9th yet, though).

Otto, thanks for the Neumann live recommendation (and the quote). I look forward to finding it.