Two other options are blood fin tetras and White Cloud Mountain minnows. Both gorgeous fish that are hardy and don't require much maintence.
Please know that bettas are not cold water fish, and do require tropical temperatures to be comfortable and to be active, happy and live long.
I also recommend that if you have a filter, you use it, especially if you decide to go with goldfish. They produce a ton of waste and are messy eaters for the most part. Here's a site with some more info: http://homeaquaria.com/best-freshwater-aquarium-fish/