What should my first adult bike have? I bike a lot and I'm looking to spend £400-800 on a full size bike. It must have full suspension, detachable front wheel, preferably room for a minipump and a large water bottle (without using the far bottom side of the frame). I see this is close to a discussion, but I think there are some obvious answers I'm overlooking. Bike or shop suggestions welcome.

Update: I commute (half off-road), use the canals, in-town and between-town roads, and a lot of off-roading. I would like to be able to manage my bike well, hopefully learn to do more than just replace tyres/tubes. It will occasionally be carried by car. I use bike lanes, pavements and the middle of the road fairly equally.

How complex are softer drivetrains and disc brakes? I'm not familiar with either of them.
£ so if you are in the UK, check out Edinburgh bike coop if there's one near you.

Definitely get disc brakes. Opinions on full suspension bikes differ - it used to be said that if your are spending less than $1000 don't get it. But I don't do extreme downhill so don't really know.

Most mountain bikers use camelbacks rather than water bottles because off road the bottles get covered in dirt (=cow shit) and you catch lurgy and die.  You can always add a water bottle holder later.