I don't know about "5" least favourites but here's a few for some fav artists of mine:
U2
How To Dismantle An Atomic Bomb - Cheesy and lame attempt at another Joshua Tree. Poor lyrics and terrible production. Made-for-the-charts hit single sound throughout. Virtually no album feel and hardly any atmosphere. Sorry, kath!
The Beatles
Let It Be - I don't hate it or anything but it bores me a bit sometimes.
R.E.M.
Around The Sun - Not sure if this qualifies. I've not even heard the damn thing except for a few songs. And I have no motivation to give it a try, based on the terrible reviews!
Murmur and Reckoning - They're okay but I don't get the indie hype.
Pink Floyd
The Final Cut - Overblown drama from dominating Roger Waters. Has a couple of nice tunes but overall it bores me.
Led Zeppelin
Presence - It's alright but I like it even less than In Through The Out Door which I actually don't mind. I suppose Coda doesn't qualify as a studio album.
Radiohead
The King Of Limbs - They're too far up their own asses now with this electronic sound they started in the year 2000 with Kid A which was brilliant. I even enjoyed 2007's In Rainbows to an extent. But this one is a lame duck.
Tori Amos
Probably... Abnormally Attracted To Sin, but it's not fair. I haven't even heard it. Night Of Hunters was okay but definitely among the least fav albums.
Metallica
St. Anger - Shittiest production I've ever heard combined with some asinine lyrics.
Pearl Jam
Riot Act - I really like roughly half of this album but the other half bores me.
Oasis
Be Here Now - It's not all bad but definitely inferior to the 2 albums that came before it. This album features way too many extended choruses and unnecessary walls of sound.