N. ventricosa is very easy, and it will survive cooler
temps (although not thrive on them). It also gets neat
looking pitchers, with the characteristic "coke bottle
cap" medium-ribbed peristome.
Many lowland plants are "easy", IF you can give them the
hot temps they desire. Among these are rafflesiana, and
gracilis, as well as many, many, hybrids. These plants
can be potted up in peat/perlite/fine orchid bark mixes,
watered, and they will do well, if you give them warmth
year round.