Hey p-daddy,
I'm pretty much still a noob in the world of planted aquariums and this fourm is an invaluable resource to 'getting things right' the first time!
I have had my new planted aquarium for about 3 months now including the cycling period. I have a 20 gal, 3.25 watts per gallon, pressurized commercial co2, an assortment of ferts, and literally just (yesterday) pinned down my fert routiene, (i hope)...
That being said, prior to say, 2 weeks ago, my tanks parameters were all over the place for a period of 2.5 months: no co2 injection, too much light, minimal nitrates, minimal phosphates, minimal hardness. What i had going for me was a flourite substrate, the addition of organic carbon (Excel), potassium (fish flakes and Flourish potassium) and water changes.
During my tank noobyness and even while the tank was still undergoing a fishless cycle I added the following plants that absolutely thrived! in descending order #1 being best:
1) Water sprite (Ceratoperis thalictroides) grew to 3 times its original size, I need to trim it regualrly, awesome background and oxygen producer.
2) Narrow Leaf Chain sword (Echinodorus tennellus) spawned 7 new plants in the first month.
3) Bacopa Monnieri, growth peaks above the water about every 2 weeks and must be trimmed.
4) Pearl grass, the good stems seem to grow an inch a week.
5) Red Wendtii (cryptocoryne Wendii)
6) Egeria Najas
7) Rotala
8) Ciliata (Cryptocoryne ciliata) still alive and healthy, just a little growth 1/3 bigger?
9) Ludwigia, still healthy looking but no new growth from what i can tell.
I have some microswords that didn't do so well, arguably still alive, but much smaller than when purchased. I also had Downoi (my wife called little cabbages) that completely died...but i put them in when i was treating for ICH so the salt may have killed it?
This is just my small experience in the few plants i choose, there are probably a bunch more good beginner plants, but my top five made me feel like I was doing something right, even though i wasn't.