Just a note that N. alata and N. ventrata x alata are not in TC production so it won't be one of these. Other homecenter, gardencenter possibilities though would include the the Deroose plants - N. Miranda, Gentle, Ventrata, N. tobaica x ventricosa x khasiana (noone can say for sure exactly what it is). Then there are the Agristarts plants (off the top of my head) - N. ventricosa, N. Judith Finn. And the Gubler/nurserymans exchange - N. Ventrata, N. unknown maxima hybrid.
I may have missed a few but those are the most common ones.
btw Dave, N. ventricosa does have wings when it is still a small plant with juvenile pitchers. Although the plant in the picture is large enough so that if it was N. ventricosa it would have probably lost it's wings. However the couple pointy projections on the lid seem to indicate that it is still in a somewhat juvenile stage despite it's size. Other aspects such as leaf shape support hybrid origin so I would say it's safe to eliminate N. ventricosa as a possibility.
Tony