To be honest, I take whatever they do. As long as the band is happy with what they do, I'm in. But if I could chose or decide about the next album, I would go for this:
A mixture between their stadium rock, heavier rock and experimental rock songs (Supremacy, Survival, Stockholm Syndrome, The Handler, Animals, etc.) and more stripped down or more calm rock songs such as the beautifully written and produced "Save Me". I would also appreciate 1-2 acoustic tracks as well as 1-2 funky rock songs as "Panic Station" is. And a melancholic, electric song in the style of "Isolated System" or "The Void" shouldn't be missing. I would also really appreciate if they would include choirs again in 2-3 songs. I love the choir vocals in "Survival" or the gospel version of "Something Human".
As you may notice, I'm a fan of their album "The 2nd Law". The 2nd Law arena as well as the stadium tour was my favorite Muse tour so far. Needless to say that this was my favorite Muse era. But tastes are different, I got that.