In reply to mick taylor:
Then of course, still in Glen Shiel you've got the South Cluanie Ridge, all 7 munros if you've the energy.
And the north side of the glen is equally good: you can combine the 'three brothers' and Five Sisters into one massive day. Or really go large, and do a circuit of Gleann Licht via the full length of Beinn Fada (aka Ben Attow), Ciste Dubh, the 3 Bros and the Five Sisters. That'd probably be best over two days in winter conditions.
Sgurr nan Conbhairean to Mullach Fraoch Choire is great too. I prefer it as a logical horseshoe from the Glen Affric side, but it's not too contrived to do it from Glen Shiel instead. Note: the south ridge of Mullach Fraoch Choire is a grade I climb in winter, short but quite entertaining.
I haven't even got on to the hills north of glen Affric, but they are ace as well. Pick of the bunch is Sgurr nan Ceathreamhnan, which is a full on walk whichever way you come at it. A bit more do-able if you have a night out somewhere along the way - Camban bothy for instance