For me, a big part of buying albums is getting the packaging. This is why I don't like buying digital albums (or just copying or illegally downloading music). I really like to be able to hold the artwork and look at it thoroughly. I like to get to know albums I buy, and it's hard without packaging.
I hate buying CDs from the early 90s that just have no packaging. You get the regular old jewel case, the CD, and the tiniest liner notes possible: just a single sheet, folded once. Maybe it contains lyrics to one song and the credits. I mention the early 90s, but really it started in the 80s when CDs first came out, and when albums were being issued on CD for the first time, often the record company just shrunk the 12" vinyl artwork and crammed it into the 5" CD case.
Some of the worst examples are a few of the Cure's albums, like Boys Don't Cry (1980) (actually an American compilation basically consisting of their first real album, Three Imaginary Boys (1979) and their first three singles), Devo's Duty Now for the Future (1978) (containing literally nothing on the sleeve but a catalog listing from the record company), Moby's self-titled debut (1992), or Electronic's self-titled debut (1991). (I should note that many of the Cure's later albums have much better liner notes, like Disintegration (1989) and Wish (1992).)
[The Cure – Boys Don't Cry (1980). Not much more here than the bland, non-band-approved art.]
[The Cure – Disintegration (1989). A major improvement – interesting, plus lyrics and more art inside.]
[New Order – Power, Corruption, and Lies (1983). This is the original cover by Saville; later CD reissues added the band name and title. A great cover picture.]
[Joy Division – Unknown Pleasures (1979). Another of my favorite Saville covers. Some of the inside art available only on the vinyl version inspired an oil painting I did in high school.]
[OMD – Dazzle Ships (1983). Another Saville work. The vinyl version has a unique design with small holes designed to let the different colors of the inner sleeve come through while pulling the inner sleeve out. A great design.]
[Neil Young and Crazy Horse – Everybody Knows This Is Nowhere (1969). Simple, but I love that shot so much, and the way it was printed made it grainy in a sort of good way.]
[From the sleeve of The Smashing Pumpkins' Adore (1998). This has always been one of my favorite shots; I painted my own version. The sleeve is thick due to several pages of photos and complete lyrics in different fonts and arrangements.]
[The Smiths – "This Charming Man" single (1983). Morrissey always found interesting shots of his favorite actors and models, and this was always one of my favorites.]
[Radiohead – Kid A (2000). This art was mind-blowingly arty and thus great.]
[Neil Young with Pearl Jam – Mirror Ball (1995). A great cover that doesn't even include words.]
[John Lennon & Yoko Ono – Wedding Album (1969). Whoever took this photo had a Japanese edition with all the inserts, which are displayed here.]
The best thing is when albums are reissued, usually with remastered sound and bonus tracks. Not only do I love bonus tracks, but these reissues usually have full lyrics and little essays and period photos. I adore these reissues. Echo & the Bunnymen's reissues are notable for all the above, plus an extra paper outer sleeve, but no lyrics (which is even weirder considering the original CDs had printed lyrics). The Cure's reissues (and the reissue of the side project The Glove's Blue Sunshine (1983, reissued 2006)) are fantastic: a whole second disc of bonus tracks, lyrics, photos everywhere, little essays and notes. Wonderful. The Byrds' reissues lack lyrics but have song-by-song notes. Not every band gets it right, though: Psychedelic Furs and Siouxsie & the Banshees reissues are disappointing for the lack of much of anything but a few bonus tracks and notes.
[Echo & the Bunnymen – Ocean Rain (1984). I love this album and its cover. The packaging of the reissue helps, but lyrics would've been great.]
[The Glove – Blue Sunshine (1983). In case the name of the band wasn't clear, the cover makes it clear that this is a Yellow Submarine reference. The reissue keeps the design up throughout the entire lavish liner notes booklet.]
I could mention many more bands and reissues, but I figure that's enough. Feel free to make suggestions for notable good or bad packaging that I failed to cover.