Automatic:
Anything Devin Townsend related (not more The Hummer / Devlab though).
Anything Ginger Wildheart written (Wildhearts, Hey! Hello!, Mutation, solo, etc...).
Both are smaller artists who've released so much great material and I like to support their careers as much as possible (within reason).
Almost automatic:
Def Leppard - the first band to ever leave my jaw on the floor with how incredible they sounded so many years ago. Also, Hysteria is my second favourite album of all time and despite the special sauce being absent since Clark's death they still deliver consistently good material. Even their worst albums (X and Slang) are solid and have the occasional outstanding moment. Their latest is the best album they've done since Clark died despite Joe's voice being buggered in its upper register.
Iron Maiden - After H left and Bruce was doing that horrible thing with his voice far too often they stopped being an automatic purchase, then they hired Blaze and they became a won't purchase. Since Bruce and H returned (with Bruce now singing properly again) they're back to where they belong on top of the heavy metal world. I can't imagine not buying any future records from here on in, but you never know... I didn't think much of Book Of Souls and Dance Of Death has not aged at all well, Paschendale aside.
Queensryche. They're responsible for my favourite ever record and if they'd just stopped after Empire they would, hands down, be my all time favourite band. Even if you include the three other diluted DeGarmo included albums they'd probably still be my favourite band... Now the rotting root has been removed from the band and we're back to having Wilton properly contributing to songs and sound I'm back to cautious excitement about releases. They'll never be the same as they were when DeGarmo/Wilton/Tate were all contributing properly, though.
Beast In Black (continuation of the first three Battle Beast albums...). I just adore Anton Kabanen's writing. Cheesier than a triple cheese pizza dipped in fondue and I love it. However, I can see a point, eventually, when enough will be enough and I'll end up feeling like I've heard the album already.
Scar Symmetry. They're a listen-as-I-work kind of band more than one that regularly demands my attention and as such there's a surprising number of songs I can't really remember if I look at the track listings as it all rather blends into one. Whilst an album is playing then I do enjoy it... bit weird.
Ayreon/Star One. I've not yet not bought an Ayreon album, but they're getting pretty ponderous and fairly samey now. Still, there was enough to like about The Source that I bought it anyway. The two Star One albums are ace and I prefer that side of Arjen's writing and would love him to do another, though it seems like he might've fallen out with Russell Allen again so either it won't happen or he'll have to get in someone else to do those parts (Jorn Lande maybe?).
Mastodon. I didn't like The Hunter nor Once More Round The Sun very much but Emperor Of Sand is marvellous and I've got all the studio albums so far. They're almost one of those bands I want to like more than I really do.
Would be automatic if the possibility of new releases existed...:
Type O Negative.
Rush (well, until they make an official "Peart has retired" statement I guess it's never say never territory but it looks extremely unlikely now).