Symphony box set recommendations

I'm looking for recommendations for box set cds containing the collected symphonies of Dvorak, Mahler, Bruckner, Shostakovich and Prokofiev.

Ie, which conductors' versions would you recommend?
Dvorak Complete Symphonies: Neumann/Czech Phil on Supraphon

I don't listen to 1-3 much, though. You could get Rowicki's twofer of 4-6 and the twofer of Szell's 7-9.

For Mahler, the Bertini is a very strong set.

For Bruckner, there are the two Jochum sets, the first on DG with Bavarian RSO and Berlin SO, and the second on EMI or Brilliant Classics with the Dresden Staatskapelle. Not everyone responds to Jochum's flexible tempi. Skrowaczewski's is an excellent modern set, and he includes "0" and "00". Here's a listing of complete sets.

The only complete Shostakovich I have is Kondrashin on Aulos, which has compromised sound on some of the recordings (nothing that really bothers me much but YMMV). I've heard great things about the Kitayenko on Capriccio SACDs, Jansons on EMI, and Barshai on Brilliant Classics.

I do have the Kitayenko Prokofiev set, and that is the set to get now. He includes both versions of Symphony No. 4.
For Bruckner, I would go with Jochum's Dresden recordings. For me, no one else ever really consistently got Bruckner right. It is my opinion that no other composer's work suffers more from poor interpretation than Bruckner. I haven't heard enough of his DG recordings to comment, although I will say Bruckner's DG Te Deum is the one to have.

On Mahler, I suggest the DG recordings by Leonard Bernstein. He does some very interesting things, some of which I like and some I don't, but his interpretations are unique. His 2nd is particularly noteworthy, but I also like his 6th the best of any I have heard.

I have both the Barshai and the Jansons Shostakovich cycles. They are both very good. I would give the nod to Barshai if I had to pick one. The Jansons 4th is strikingly better than any other I have heard, and their is a breif recording of Jansons in rehearsal that makes for interesting listening.
For the Dvorak symphonies try the one with Istvan Kertesz and the London Symphony Orchestra. They were recorded in the 1960's but the sound quality and performance is excellent.

Shostakovitch - Haitink's cycle is great. The premier Mahler conductor today is Claudio Abbado. For Bruckner, you can't beat Giulini, but I don't know if he ever recorded all of them. Not sure about complete sets of Dvorak or Prokofiev.
I should have added that I'm referreing specifically to the Giulini's VSO recording of 2 now on Testament and the DG recordings of 7-9.