Conceptually, I like shapeup. I think spiral model is fine - I'd argue that a lot of "agile" shops are closer to spiral.
Now, there are tools in agile that I'll vehemently defend, such as continuous integration and retrospectives. I'm a fan of most of the principles, such as "Continuous attention to technical excellence and good design enhances agility." But we are now at a point that if we're going to argue that "agile doesn't work," we've had enough time as an industry to gather around an alternative.