Not very difficult for me to rank them:

5) Empty Space: A Haunting, by M. John Harrison – possibly jetlag while reading it, but apart from Anna Waterman I found the characters unengaging, and I had difficulty following the plots and grasping how or why they intertwined.

4) 2312, by Kim Stanley Robinson – rambling and dubious but with a couple of good set-pieces.

3) Intrusion, by Ken MacLeod – a good book but quite a tough read, also tantalises with mind-blowing stuff happening off-screen.

2) Jack Glass, by Adam Roberts – a lot of clever stuff; a lot of entertaining writing; ending perhaps a bit too clever, but a good read.

1) Dark Eden, by Chris Beckett – I really liked it, subverting a lot of expectations of young hero versus conservative small society on an abandoned planet.

I'll be happy enough if any of my top three wins.