Hello fellow alchemists. This is a simple guide that shows some of the best potions I've come across, as well as the reagents needed to craft them. I'd add a Poisons section, but as poisons are NYI, it'd be kind of useless. Also, any potions that had good effects but one negative effect were left out. Lets get started.

Invisibility Potions

Emergency Potion (Blue Entoloma/Columbine/Namira’s Rot)
-Invisibility
-Unstoppable
-Restore Health

Movement Potion (Blessed Thistle/Blue Entoloma/Namira’s Rot)
-Invisibility
-Speed

Sneak Attack Potion I (Blue Entoloma/Namira’s Rot/Water Hyacinth)
-Invisibility
-Spell Crit
-Restore Health

Restoration Potions

Rejuvenation+ (Bugloss/Columbine/Mountain Flower)
-Restore Health*
-Restore Stamina
-Restore Magicka

Combat Potions

Predator Potion (Columbine/Dragonthorn/Namira’s Rot)
-Restore Stamina
-Increase Weapon Power
-Speed

Melee Master (Blessed Thistle/Dragonthorn/Water Hyacinth = Wormwood)
-Restore Stamina
-Increase Weapon Power
-Weapon Crit

Melee RestoCrit (Dragonthorn/Columbine = Mountain Flower/Water Hyacinth)
-Restore Health
-Restore Stamina
-Weapon Crit

Melee Murderer (Columbine/Dragonthorn/Wormwood)
-Restore Stamina
-Weapon Crit
-Unstoppable

Magick Master (Cornflower/Lady’s Smock/Namira’s Rot = Water Hyacinth)
-Restore Magicka
-Increase Spell Power
-Spell Crit

Magick RestoCrit (Bugloss = Columbine/Lady’s Smock/Water Hyacinth)
-Restore Health
-Restore Magicka
-Spell Crit

Magick Murderer (Columbine/Lady’s Smock/Namira’s Rot)
-Restore Magicka
-Spell Crit
-Unstoppable

Tanking Mage (Bugloss/Columbine/Namira’s Rot = Wormwood)
-Restore Health
-Restore Magicka
-Unstoppable

Buff Potions

All positive buffs are accompanied by negative buffs, rendering them semi-useless.

Most useful reagents (# is how many times it was used):

9: Columbine
6: Namira’s Rot
5: Water Hyacinth
4: Dragonthorn
3: Blue Entoloma, Bugloss, Wormwood, Lady’s Smock
2: Blessed Thistle, Mountain Flower
1: Cornflower
0: Emetic Russula, Imp Stool, Luminous Russula, Nirnroot, Stinkhorn, Violet Coprinus,
Whitecap

Well, there you have it. Have fun with your potions!

Note: The names aren't what they're actually called. I just called them that.