The team is very important - primarily because business models can and in fact do change, but is the team that holds the business together. Its important to have team members that can challenge and push each other to get to a level that neither can get to alone. So, the team is certainly the most important.
A large market size is also important - "its better to have a smaller slice of a fast growing, big pie" than to be the big fish in a small pond, other things being equal.
Most importantly, today, "path to profitability" is also important - its ok to have a cool product/amazing technology, and an inkling of revenues but sooner than later, the best businesses are the ones that become self sustaining and need cash only for growth and not for working capital / sustenance.