The 3 Mont Blanc route is quite scenic but not a challenging one, the only steep part is the face of Mont Maudit still very moderate.Overall a good intro to the Mont Blanc range.
If you do that I would suggest you to sleep at the Refuge des Cosmique, or on the glacier for a couple of nights, and the first day go for a day climb like the Cosmique Ridge, more technical of the the 3 Mont Blanc Route or the Traverse Midi-Plan, beautiful and varied but not too difficult.
On the 3 Mont Blanc routes you want to start around midnight therefore you can get o top of Mont Blanc at sunrise, and enjoy the spectacle and avoid the crowd descending...
It depends on you skills for other more technical routes, but anything on the Italian side is longer and more challenging in the D TD range.
The routes on Cervino are always very crowded in the summer it is like a the queue at the gas station....I decided I will not climb that mountain for this reason...and the Swiss guides can be quite aggressive...unless one day I will be good enough to do the North Face.....
Anyway enjoy the trip!