I've worked on dull software with interesting people and interesting software with dull people. The people are easily the deciding factor for me.
In an interview the best you can probably do is to pay close attention to how they describe the role and the team, especially non verbal cues. You can try to ask some questions which give some insight (what's the team culture like, what's the worst part about working here, etc) but a lot of interviewers will give non-answers to those sort of questions.