Aberofyle is a lovely little town with nice pubs and lovely walks. Aberfoyle also hosts a Go Ape location. If you are only on a short visit I wouldn't necessarily expect you to fancy this as it takes up a good 3 hours, but it is brilliant fun!
goape.co.uk/locations/aberfoyle
Lomond Shores as previously mentioned has some decent shops, but there are bound to be some Christmas markets on at this time of year. There will be FB pages/events, so I strongly recommend checking this out. see below
www.facebook.com/events/2429916427276250/
Milngavie is a town closely located to Aberfoyle. It is the starting point for the West highland Way, so nice walks to be had and some decent bars/eateries aswell I am sure.
My favourite place in all the world is Luss so I echo the above posts and recommend a jaunt out that way. The Village Café is lovely - and affordable.
Balloch/Balmaha is a nice area very close to Luss which also has nice parks/walks and nice places to grab a bite to eat.
Glasgow City centre has the myriad of museums previously mentioned. Kelvingrove Museum is wonderful. I find the Transport museum dull but that's likely due to being dragged there every year of childhood by the school! [ grin].
Buchanan Street is the shopping hub for the city centre.
Bath Street is the trendy bars.
Sauchiehall Street is the student-y area, plus nice restaurants.
West End is the higher end bars & restaurants. Ashton Lane is 100% worth a visit of an evening. Ubiquitous Chip is stunning for food, and Jinty McGintys bar is lively. I would recommend a walk along Byres Road from Ashton Lane, to visit Oran More, which is a truly spectacular pub set in a converted church.