Zebra Danios would probably be OK. They can get nippy but "usually" do not bother other fish when kept in a group of 5 or more. Since you have live plants, a school of small tetras would probably look nice (neons/cardinals/glowlights). They should be kept in a school of 6-8 or more. Also, tetras and danios (minnows) are of same temperment. A nice addition would be Oto cats about 3 is good for 10gal. The neons and otos are very small and with the rule of thumb of 1"per gallon you can count 2 smalltetras/Otos as 1". You can add both of what I mentioned and it would be manageable, slightly overstocked, but manageable with routine maintainance and water testing. There are many other fish that can go with bettas.Just be careful of very colorful, large finned fish (fancytailed guppies,gourami's etc.) they sometimes can be a threat to the betta, mistaken for an aggressor,and the betta could attack as if it is another male betta.Also, any fish profiled as fin nippers.

Cory Cats are another popular addition with bettas, Very reindly and pretty, Again best kept in large groups. 10 gal may be a little tight.

I have just completed exactly the same except mine is extremly heavly live planted.

You are extremly limited. Forget about the Danios as they can be fin nippers (the last thing you want.
Most Cat fish get too big and should bekept in schools.

I would suggest Cardinal Tetras over Neons as thery are stronger and less prone to diseases. No more that 7

The Ottos are an excellent choice I have 4 in my tank.

The total depends on several things plants & filtration.

Forget about the old useless 1ins to the G it is totally impractical eg a 3ins Kuhli and a 3ins Betta. The rule is common sence only not the rule of thumb.
www.fishprofiles.com

This forum could be of more help.

Keith

Thanks for the suggestions, guys. I did my research on all of the fish mentioned. I think I may hold off on finding new companions for my Bettas and just buy some more plants for the aquarium, because it will be a tight squeeze and my Betta has a lot of favorite hang-out spots, and I don't want to impede on his territory. I wish I had a bigger aquarium, but cannot afford one at this time :( However, when I am able to buy a bigger aquarium, I will definately be purchasing a group of cardinal tetras, and just let them reproduce! They are beautiful! And it must be so relaxing to watch them swimming around together...
Thanks again.

Jenny

If you have a planted tank the cardinals will be ok with the betta. They will probably avoid him and keep in a school because of his presence. If you dont feel comfortable thats fine. 6-8 Cards put very little waste out so it is manageable especially when moderate to heavy planted. Cards also like the same food as the betta (aside from betta pellets). Oto cats are also good. They are considered not that attractive, but they are a great addition for a planted tank, keeping algae low and give alot of activity. They are never aggresive and the betta probably wont even bother with them. If you can find the Zebra Oto's thay are more eye-pleasing than the common. They are both little suckers, and their antics make up for lack of color.Again 3 would be fine in the 10 plantted tank.

So... the min. # of Cards is 6? The only thing that I am afraid of is that my Betta will feel inhibited. My last Betta was King of the Tank, swimming actively everywhere, then I added a Cory fish and the Betta just retreated into a corner, until the Cory died. The Betta I have now is less active, but he has a couple "spots" in the tank, and I want him to always feel free to access his "spots". Actually, it's hard to tell exactly where his spots are, because, as soon as anyone walks into the room, he flutters up to the front of the tank and swims back and forth, hoping for a bite. Sometimes I try to sneak into the room, and observe where he is hanging. I think he mostly hangs out on the one side of the tank, farthest away from the filter (which makes sense as I know Bettas like stagnant water). How about the Cards? Do they prefer stagnant or moving water? I did research this, but got contradictory info., and there is no better teacher than experience...

Jenny