The swiftest I've had recently were bike-components.de
Bike24 seem to hold on to the order 3 days before doing anything (and that's specifically ordering on a Tuesday not in any of Germany's large number of weeks with public holidays*), then delivery lightning quick.
CRC - last 2 orders have been 15 day turnaround (makes planning orders near vacations etc. impossible)
Superstar were very quick.
Wiggle managed a 10am next day delivery in Germany for a 4pm GMT order once, just with whatever their basic delivery is.
Even better - another Wiggle order came via a courier that uses a local bike store as a parcel collection point
(* just a note for those in UK who do order from the regular German bike stores... May/June has a lot of holidays)