It looks like a Dahlia with blue Lobelia erinus in the background.

Yep, looks like a dahlia. I wonder if the blue in the background might be a deep blue/purple petunia?

Depending on where you are located, the dahlia may come back, with a little extra mulch on top of it for the winter, once it has died back, be careful about the stems - as I recall, they are hollow, so can be an avenue for water and rot to get to the tuber.

If you are in doubt about its survival in the ground, then dig the tuber once the top growth has died back, trim off the stems to about 3-6", let the dirt dry in a protected spot, clean off/brush off most of the dirt, and then store the tuber in barely damp sawdust or peatmoss - you don't want the tuber to shrivel up, nor do you want it to rot - in a cool spot that won't freeze. Check the moisture levels periodically. Re-plant in the spring about when the last frost is forecast - only the new shoots would be in danger if they have started to sprout - the tuber in the ground would come to no harm from a late frost.

If you have it in a pot, you can leave the tuber there, and follow the suggestions above without unpotting it and storing it in damp sawdust, paying careful attention to the moisture levels.

My guess would be Dahlia, too... as to variety, there are SOOOO many, you'd really just have to look on one of the Dahlia Society websites (and there are PLENTY of them out there with just SCADS of pictures).

Happy Gardening!
Jeff