I visited the Albertina in 2013 on a trip to Bavaria and Austria and I remember spending half a day at the museum which was most impressive. The collection includes works bei Claude Monet, Kasimir Malevich, Pablo Picasso and many more.
Even if you just have time for a brief stroll I guess you may find it worthwhile.
Do you have any favourite museums that you visited on any of your trips? Please share! :)