dd has lights out at 7.40pm most nights but she stays up till 8pm (or just after) when dh plays football after work on a Friday - they have their 'Friday chat'. My lo's refuse to lie in at the weekend so we dont deviate much from their usual bedtimes.
on a weeknight she and ds (14 mo) have a bath at 7. dd has a story read to her, then is allowed to read til 8. on a weekend it is til 8.30- though xfactor on a saturday replaces that atm... (this seems a common theme )
I used to have her lights out at 7, then it moved to 7.30 but she was waking up way too early. She is still a reasonably early riser (with occasional sleepathons to catch up) but this seems to work.
Bath at just after 7, then supper and a bit of telly and in bed by 7.45 or so - weekdays and weekends. She's up by about 6.45, so any later and shes a nightmare! One of her weefriends doesn't seem to go to bed --- will often appear at our door at 9.30 asking if DD coming out to play!