Virtual analogue synths sound pretty darned good these days, but if you're looking for a 'real' and playable instrument that's based on proper circuitry, you might want to consider Analogue Solutions' Leipzig-k.
This is the keyboard version of the rack-mountable Leipzig that MusicRadar has already reviewed - it throws a 37-note velocity-sensitive 'board into the mix. An extra LFO/VCA has also been added; the depth of the LFO can be controlled by the mod wheel.
The addition of a headphone jack, meanwhile, means that you can play the Leipzig-k in private.
Otherwise, the specs are very similar to those of the rack model: the inclusion of a Moog-style filter helps the Leipzig sound suitably vintage. It looks the part, too, coming in a wooden casing and with aluminium-topped knobs.
The Leipzik-k costs £899, though this is without tax and delivery. Demand is apparently outstripping supply at the moment, so get your order in at the Analogue Solutions website if you want one.