<Hmm, I think I hear Shine on You Crazy Diamond calling me.....>
An excellent choice, except that's from Wish You Were Here, not Dark Side of the Moon. Wish You Were Here is easily one of Pink Floyd's best albums, and a great one for wallowing. The title track is very mournful, Shine On You Crazy Diamond is a great lament, and Welcome To The Machine is good old fashioned dark-and-sinister. Even Have A Cigar has a brooding element to it. Excellent wallowing-in-a-depression music.
Also excellent for wallowing, and this was mentioned earlier in the thread by Sir Osis of Liver, is Alice In Chains' Jar of Flies. The song Don't Follow is a great one.
Another good wallower: Dire Straits' Brothers In Arms from the album of the same name. The front side of that album is pretty fluffy, bouncy stuff, which is the side they're most famous for, which is too bad, because the second side is really outstanding music.
There isn't enough bandwidth to encompass the list of Blues artists responsible for great music in which to wallow. Some choice examples: Robert Johnson, Sun House, Billie Holiday, Leadbelly, John Lee Hooker, B.B. King, Muddy Waters, David "Honeyboy" Edwards, Bessie Smith ... you get the idea
Great pick-me-up-and-get-me-out-of-depression music is, as Henry mentioned, AC/DC. There's just too much raw power there to sit still - it's great to exercise to, and generally get motivated about things. Everything they produce grabs you by the insides and slams you into an electric fence.
Iggy Pop's got some great songs to rev up to as well, like Lust For Life, Kill City, and Cold Metal.
Pogues: nothing like loud, drunken, Celtic rage to get you pumped up.
Beethoven is great for getting the blood flowing: Try Symphonies # 2 and #9. Early 19th century Rock-and-Roll.
The Cult: Electric. The whole album - insert into CD player, push play, feel blood pressure increase.
Ladysmith Black Mambazo. Accapella music that elevates the spirit.
Stevie Ray Vaughan has plenty of Blues to wallow in, but he's also got a great one to cheer up by, off the Family Style album (assisted by brother Jimmy Vaughan, blues guitarist par excellence in his own right), called Hard To Be. Get-up-and-dance-around music.
Look for a CD from Rhino Records called Risque Rhythm. Its various R&B tunes from the 50s that were the target of a "decency" crusade in 1954 because the lyrics are suggestive. The music positively jumps - if you don't feel good listening to this, check your pulse.
There's lots more ... there always is
Warrior Poet