Fra_Diavolo has a good idea. If you can avoid buying any food while on le MSM, so much the better.

If You have some time left, visit St Malo. Lively and beautiful intra-muros

another vote for PalenQ's suggestion of staying nearby. Last fall I stayed at one of the motels across the bridge from MSM. There are frequent shuttles from the main parking lots that stop in front of these hotels, and you can park by your hotel instead of the more distant visitor lots. By spending the nite you can visit the general area such as Cancale or driving thru the Calvados countryside, even visit Dinan if you want. Then arrive 4pm or so when tour buses are leaving and you'll have far less crowding, and go back at nite after dinner to see it lit up. I made a last visit in the morning around 8am before leaving.

The hotel I stayed at, Le Relais du Roy, was decent enough and they have an attached restaurant that was one of the best dinners I've had in France! Note that the restaurants in the area close early so plan to be seated by 7pm.

Of course you can stay on Mont Saint Michel if you are really attracted by the magic of the place, and not really worried by the value for money. Otherwise, you can consider towns not very far which still allow you to visit Mont Saint Michel in the evening when it's quiet : Saint Malo, Fougeres, Combourg, Dinan, Avranches...

We stayed 1 night on the Mont and it was one of my husband & my most memorable experiences. The peace, the opportunity to wander around with virtually no one around on a beautiful night was very special. We wandered down to the entrance and enjoyed gazing up at the Mont in all its glory with not a soul nearby. Early the next morning we walked the paths around the outside, watched the sunset and tide roll in and had one last view gazing up before all the people rolled in.
We stayed at Le Mouton Blanc, nothing flash but did the job.
The sounds, views and atmosphere will stay with us as a special experience for a long time to come. We are so glad we did it.

Reading all the suggestions... I'm travelling with friends next June and they prefer to have a view overlooking Mont St M rather than being on it...I've tried booking Le Relais du Roy and they are showing full already. Any other suggestions for a view hotel? I've looked at the reviews for the Relais and at $1000 AUD for what appears to be not very nice rooms I need some more specific suggestions?.. Any out there?

schnauzer... i have often found that smaller hotels show "full" if you try to book too far out. try a bunch of random dates around that time or after... if they all show 'full' then that's probably the situation. ??