Chamonix is nearly unbeatable. If the conditions are excellent and you are a competent off piste skier. Otherwise it's just pretty good.
The downsides are that it does not consist of linked ski areas like many other resorts and hence you tend to ski a different area each day and queuing for a bus at the beginning and end of the day can be a pain.
That said it is my favourite short break destination and is very quick an easy to get to from Geneva airport. I'd recommend hiring a car....and if you do so make sure you hire one from the Swiss side of the airport. This way you automatically get a car with winter tyres and snow chains.....rather than having to pay extra for chains and risk summer tyres if you use a company on the French side. The Swiss Motorway vignette (Toll sticker) is also included on Swiss cars and this enables the quick easy route to and from the airport.
You regularly need winter tyres, even in March, on the road up to Argentiere.
We usually fly Easyjet and stay at Gite Le Belvedere in Argentiere
Last year when we were there, a lot of new snow was forecast one night, but it didn't arrive. However we heard at breakfast it had dumped it down in Courmayeur......so we jumped in the car and 40 minutes later we had the most amazing skiing in Italy!