I've heard Daemons as well. Something similar to: 2 screamer stars, a unit of spawn + hq and horrors for sunmoning. I don't remember if fateweaver fits in or not. Try for invis on the spawn, with cursed earth and grimoire on the screamers so that they can summon accurately in your opponents face.
I'll echo some from above:
White scars bikes. But really any white scars. A white scars chapter master is popular in death stars because of hit and run.
Speaking of death stars, I hear centurion star is doing well. Invisibility and/or levitate + white scars beatstick lord.
Eldar/DE still have seer star, beast star, and wave serpent spam. Any list is bound to have at least one wraithknight an some wave serpents.
I hear Tau aren't making much of a showing at tournaments anymore. Riptides just ain't what they used to be without buff commanders and eldar psychic buffs. O'vesa star still works but the only other thing you can expect to see now is the occasional gunline with broadsides and some riptides. Honestly the only Tau you might see is in the form of the tank-hunting formation.
It also depends heavily on that tournament's mission pack.
Heavy emphasis on kill points? You're going to see lots of death stars.
Emphasis on board control, for example, the ones that allow you to score points on objectives throughout the game? Again, more death stars but also blob guard with a knight or two. That list has a lot of muscle to push the opponent off objectives all game.
For more of a standard tournament you'll see more armies that are either fast or MSU. Fast are bike armies, death stars, etc. MSU are Marine drop pod armies, rhino rush, etc.
Necrons are good at all types. The lord on chariot can smack an Imperial Knight around. It's got answers for everything between guass, the chariot lords and fliers housing objective secured troops that you can drop on objectives the last turn of the game. And because of time limits, you always know when that last turn is.