Your must read recommends

[Montero]

Anything by T Kingfisher. Discovered her earlier this year and galloped through her entire output. Some inclines more towards horror. My favourite is Paladin's Grace, followed by Swordheart ISBN 978-1-61450-463-4, with the Clocktaur Wars duology starting with Clockwork Boys ISBN 978-1-61450-406-1 following that. (All are in the same world, with overlap but you can read one without the others. The chronology is Clocktaur, Swordheart, Paladin.)

Juliet E McKenna Green Man series from Wizard's Tower Press.

AJ Fitzwater - Cinrak the Dapper and No Man's Land

I will come back and add ISBNS where I haven't - internet link is acting up and I can't get at them.

 

[Juliana]

Not sure if you're still taking suggestions Jo, but for British SFF YA: Tom Pollock's Skyscraper Throne trilogy. First one is The City's Son, ISBN 1780870094 (2013 but looks like still in print).

 

[Montero]

AJ Fitzwater - No Man's Land - 978-0 -9951355-3-6
Juliet E McKenna - Green Man's Heir (first in the series) 978-1-908039-68-2

 

[Stephen Palmer]

Steve Cockayne's trilogy is great, and rarely mentioned. Brian Aldiss' Helliconia is pretty much the best Sf ever!... Except TBOTNS maybe. Make sure you have The Silver Metal Lover. Gibson's Sprawl trilogy is important still. Olaf Stapleton 'Sirius' still packs a punch. His Dark Materials. Brian Stableford's The Empire of Fear is the best vampire novel after the original one...