Hi spiffnme,

I have a few suggestions that I think you may enjoy:
($$$=premium,$$=mid,$=bargain)

Rachmaninov/Franck, Sonatas for Cello and Piano, etc.
Hyperion CDA 67376 $$$
Stephen Isserlis(Cello), Stephen Hough(Piano)

This is a brand new recording, and it is absolutely fantastic. The Rachmaninov is particularly gripping. Pricey, though!

Rachmaninov, Piano Concerto No.3 in D minor, Opus 30.
Arcadi Volodos (Piano), James Levine (Cond.), Berlin Phil
Sony Classical SK 60893 $$

Live, although you would be hard pressed to tell. Best Rachmaninov 3rd, hands down (I have 15 different recordings of it, and have heard over 40)

Bach, Solo Cello Suites 1998 recording
Pieter Wispelwey (Cello)
Channel Classics CCS 12298 $$$ (but double pak)

Very warm, beautiful tone. Avoid his earlier (1990) recording on the same label.

Holst, The Planets
Andrew Davis (Cond.), BBC Symphony
Apex (Time/Warner - budget) $

My favorite recording of The Planets, spectactular performance and well recorded too! Dutoit is nice, but 3 times the price (rhyme not intended)

Also, if you are in Canada, check out the CD bins at Chapters/Indigo. They carry a classical series done by Tring (TIM classics?) that is really good. The CDs look a little like something you might find at WalMart, but the recordings are very well done, and some of the artists give definitive performances. All performances are with the Royal Philharmonic, using various conductors. Here are a few good starters:

Beethoven Piano Concertos 1,5
Beethoven Piano Concertos 2,3
Beethoven Piano Concerto 4, Triple Concerto
Michael Roll (Piano), Howard Shelley (Cond.)

Grieg Piano Concerto, Lyric Pieces (excerpts)
Tchaikovsky Piano Concerto, Seasons (excerpts)
Ronan O'Hora (Piano), James Judd (Cond.)

Checkout the Apex (Time/Warner) series. Cheap (cheaper than Naxos, even!), but often good. For definitive sound quality (albeit high price), the Chandos label has unbeatable sound. Hyperion is usually not too far behind. Unfortunately, these labels are both UK imports, making them $$$. Brilliant Classics has taken to re-releasing some good recordings originally done on CRD, ASV and Haenssler that can be quite good too, and they are very affordable (at HMV).

I know this seems like a long list, but there is a lot of good stuff out there that is often overlooked by music snobs.

Good luck!