It looks like it could be a dwarf cavendish, but I have seen high color mini's (which don't produce fruit, but are pretty) that were small and mostly green like this.

Personally, I would never tell someone to leave a tropical plant in the ground if it dies every winter. If you don't mind caring for it indoors (warm, humid and properly fertilized) do that. Others may say you can winter it in a basement without water and they bounce right back. I won't try it, so I don't know if this works :-)

Well I heard it was doing fine and had fruit but the frost killed because they didn't cover. This plant came from one that was about 5-6 feet tall after a year and they got the original at home depot for $4.

It's all personal choice. I grow indoors due to living in Wisconsin and liking plants indoors to help raise o2 production and keep humidity up. Your plant looks very healthy, and if you got the impression I thought otherwise I'm sorry. I would then suggest that if you plant on overwintering it outside, cover it not only to protect from wind but from frost and impending winter weather. Otherwise, I would say go ahead and enjoy it indoors all winter! Just remember to water it, and keep it away from drafts (hot or cold) and use a humidifier if you don't mist it frequently. This will prevent growth from slowing to a stop.

Of the typical bananas for sale that does look like DC. I just looked and it is hardy to zone 8-9 so if the 9 next to your name is your zone, you won't have to bring it in. Of course make sure that is correct but if so I would suggest planting it and leaving it. It will always have a head start. I keep live bananas over the winter for a little foliage. I have also been getting better at cold, dormant storage which lets you ignore them most of the winter. But all of the people in town that have basjoo and get to leave them in the ground always have a head start and better overall growth. Once the mat establishes itself your main upkeep would be removing the extras you don't want.