It has to be a Crossrail, HS2, Regeneration themed - anywhere where the government is spending big money - this tends to be reflected in the property prices in the years to come. Think about it like this, if the government are spending "big money" on regeneration projects they will want to see a return on their money - and this is done by building a stronger local economy and higher property prices. For example, they are spending £14B on Crossrail and the estimated returns are £42B after a few years of running.
Reading, Twyford, Maidenhead, Burnham, Iver, West Drayton - are all good places to invest. But Reading is number 1.
If looking for value in Central London - look at "New Cross".