Scorpions spear, when he moves his hand to the front it lasts a second but easily predictable.

Jades ninja star... It takes about 1~2 sec to load.

Barakas little spike blast, he would make that fading away motion and you could always see it coming.

Hotaru's Lava Burst. You could easily jump back when you saw him shoot it out.

Nightwolf's arrow - you could see him take out the arrow and pull back the bow before firing it.

Scorpion's spear and Sub-Zero's ice blast, simply because of their noteriety. They've been around since MK1, and have become the most well known moves in the series. I've seen them so many times, I can't not expect them when I play against Sub-Zero or Scorpion.

I thought the Spear was one of the faster launching moves.

I think its harder to see coming even if you know it will at some point.

almost all the projectiles are easy to see coming. i think i hate the recovery rate on scorpions spear if it's blocked.