Jaguar please no spoilers/cheats on which ingredients make which potion. There would be no Experimenter perks if we were supposed to check Wiki for ingredients. If you want to cheat that's fine but some of us want to play as intended because it's also more fun.
Yeah I don't think healing would be much of an issue, though if I could suddenly start making healing potions that heal 100+ points I would consider making some.
Poisons though, the generally 9-12 points or whatever I could make as a warrior were hardly worth the effort. But if I could make some that do something like 50+ damage that would be something worth pursuing.
Alchemy was main skill I focused on as bow-assassin (Master difficulty). I'll give you my current estimate:
(100 alchemy, plus few items found along the way with +% in alchemy, which one puts on when mixing potions.)
1. Healing potion will heal around 130hp. Stamina potion is probably around the same. Health regengeration potion is about +100% faster regen for 5 minutes.
2. Most poisons do 44 damage, some 66, and the strongest one I know of does 110 damage (only one ingredients, don't expect to spam this, although it's still useful for tough situations).
Lingering damage health poison does 22 damage over 10 seconds (for a total of 220 damage). Plenty of ingredients for that one.
3. You will need to spend 9 perk points, plus 10th if you want Snake Blood (I use that one for RP as Argonian, and it occasionally helps but is not needed as poison is rare). What you don't need is Experimenter (remember that when you select an ingredient, other grey ingredients will be those you attemped to mix already with the one you selected), Purity (in practice, I have not run into a situation where I really need this perk; a bit of tactic and care works) and Green Thumb (it won't help you with ingredients you really need; and because economy in the game is broken - you can just visit every alchemy shop when you're passing through the town and buy ALL the ingredients, then sell back potions to make money). If for whatever reason you don't intend to buy ingredients but want to collect them, then use this perk.
4. The most important potion is Paralysis. It is very very rare that enemy resists this potion. It can be used on enemies much stronger than those affected by Fear/Frenzy (my impression). Current duration: 22 seconds.
Weaker version is 50% Slow, which works for about a minute and a half and helps vs melee.
5. Resist Frost/Fire/Shock 63%, Magic cca 22% (these two can be stacked as game first checks for magic resistance, reduces damage, checks for elemental, reduces damage).
6. Fortify Marksman: 83% more bow damage for 60s.
Weakness to Poison 42%, but I haven't used this one as it last only 30sec so not good for dragon fights, and almost everyone else will die fast enough that it's better to open a fight with a poison itself.
One thing you may not like is the fact you'll need to hit TAB a lot (to choose potions and poisons) even if you use some hotkeys.