Some thoughts
You are totally correct, you don't see a lot of talk on here about classical pieces beyond the few traditional ones everyone will recognize.
The 9th you have, is that with Szell? If it is a recording with George Szell, it is probably from the 60s (maybe even the 50s) so I am not surprised the fidelity is not the best. I have the 9th with Solti and Chicago, personally I think this is a great recording but I don't have a lot of other versions of the ninth to compare it with. If you didn't like the vocals in the standard version, you can try the alternate version with Leonard Bernstein "Ode to Freedom" (instead of "Ode to Joy"). It was used in a concert celebrating the re-unification of Germany, it should be available on Deutsche Grammophon.
There are a few of the "big" orchestras that should always sound good but the reality it with modern recording techniques even orchestras that are not so great can produce great CDs (thanks to editing and multiple takes) with hi fidelity (all really depends on the recording engineers). So while the traditionally great symphonies from around the world will be more consistent and are more likely to give a great performance live, I think on a CD it doesn't really matter as much.
In general, when looking for CDs try to get ones that are DDD (digitally recorded, mixed, mastered). You should see the DDD somewhere on the CD case, while it does not mean it will be great sound for sure it is an easy way to catch if the record company is reissuing an older recording. You will find many CDs that are cheap by famous orchestras but old and they may be AAD (analogue recording, analogue mixing, digital mastering) or ADD (analogue recording, digital mixing, digital mastering). Now all modern recordings are going to be DDD but that does not mean they will sound great, this is more useful as a guide to avoid older recordings (if you want to); sometimes there may be a great performance that you will want to get and you can live with the higher noise floor and hiss you get.
It is getting late so I will finish this up, but I will try and give you more specific recommendations later. What kind of music do you like, which pieces by the above composers did you like. I am a big Arvo Part fan, which pieces do you like so I can recommend similar ones? In general, do you like symphonies, choral works, chamber music, concertos?
I will leave you with a few recomendation off the top of my head:
- Ottorino Respighi's Roman Suites (Fontane di Roma, Feste Romane, Pini di Roma) performed by Daniele Gatti and the Orchestra Dell'Accademia Nacional Di Santa Cecilia. These are some really nice pieces and a great recording.
- Another great redbook CD is Igor Stravinsky's Rite of Sprin performed by Eric Kujawsky and the Redwood Symphony. This CD has simply huge dynamics and it a really great recording (was listed on stereophile's records to die for list in 1997)
- There is a SACD by Leonard Slatkin and the Saint Lewis Symphony Orchestra playing a Barber's Adagio for strings along with some other nice mellow pieces in a similar vain (Tchaikovsky's Seranade for Strings, etc.) Slatkin and the Saint Lewis are a great symphony, this is a nice disc even though it has Pachelbel's Canon in D which makes me want to puke
- Another SACD with similar music is by Charles Rosekrans with the Royal Philharmonic Orchestra. They play two string quartets that have been orchestrated for chamber symphony which provides a much richer sound that the original versions. Schubert's Death of Maiden and Dvorak's 'American' String Quartet.
- One of my favorite classical pieces is Henryk Górecki's Symphony No. 3 'Symphony of Sorrowful Songs'. This is available on SACD by Yuri Simonov and Royal Philharmonic Orchestra with Susan Gritton singing the solo soprano part.
EDIT: I will also add, stay away from classical collections aimed at people who know nothing about classical music. Compilation CDs are not bad, just be sure you have either heard of the orchestra or it is one of the big classical record labels.
