Skyrim Alchemist's Pocket Reference
Update 11/22/2016 - Since Skyrim SE has been out, I got sucked back in. Here is an updated page for you alchemists!
This is a compilation of the most beneficial, deadly, and multi-ingredient potions & poisons available. These were hand-picked because of their complimentary effects such as Paralysis + Lingering Health Damage or Restore Magicka + Fortify Magicka, etc.
I've additionally rated the potions with ◊ diamonds ◊ indicating the overall usefulness and availability of ingredients for each potion. A 5-diamond ◊◊◊◊◊ potion is typically the easiest and most useful. Your mileage may vary.
All the potions and poisons on this list were generated with the help of a few online Skyrim Alchemy tools: