I think UConn, Baylor, and South Carolina are three fairly obvious choices, but there is definitely some decision for that fourth spot.
While Arkansas has a lot of really good scorers, I don't think they have the size or defense required for a Final Four run. Their style of play makes them subject to a huge upset when they're doing well offensively, but they're also susceptible to getting upset by a less talented team when they have an off day.
Mississippi State has the talent to make it to the Final Four, but they have a new coach so there is some unpredictability there.
Oregon has loads of talent, but is also unproven given all their losses. They may be one of those teams that doesn't come on until late in the season.
Stanford definitely has some experienced talent and a great coach. I think I would go with them for that fourth spot.
Louisville, Arizona, and NC State could also be in contention for that fourth slot.