I can recommend the IBIS hotel in Schoenbrunnerstrasse. It is clean, nice and has it's typical IBIS comfort. The staff is very friendly and efficient. Note that booking via the Internetsite of the hotel is mostly cheaper than booking by phone! see link below. If you are looking for spacious rooms it might not be your choice, but I think the bedroom-size was OK.
it is a Smoke-free hotel, so non-smokers will be happy there. Nice breakfast buffet with a good selection.