Notable Epic/Patron powers?
I often take Ball of Lightning over Fireball because the Blaze Mastery pool requires an additional power pick to get FB. Shadow Meld is great if you are not softcap or want to isoftcap (59%) for incarnate trials. The Soul Mastery pool also has Moonbeam which may be useful come i24 and the snipe changes. We will see a lot of players switch over to the Leviathan PPP and Water Spout. The Overwhelming Force changing knockback to knockdown is going to be huge. I have never found Darkness and Mace Mastery very useful. Their damage is a little on the low side and Mace has a redraw factor. Weapons Mastery can be good if you just need Physical Perfection and the shuriken powers can fit nicely with a few character concepts but Shuriken/Exploding Shuriken have low damage as well.
If you have no end problems, try out Leviathan! It does a lot of damage and good mitigation with it's knockup ability.
Playing an Elec/Elec stalker right now and loving it, but I wanted to start planning my late-game build, and for that I need to pick an Epic/Patron pool. From what I've read, the various powers worth noticing include...
* Fireball and Ball Lightning, for AoE damage
* Superior Conditioning and Physical Perfection, if you have Endurance problems
* Shadow Meld, as a panic button
* Some people like the Snipe powers
I've also heard mention of Water Spout, I think? Is that any good?
Are there any other Epic/Patron powers for Stalkers that are really worth taking and investing in?