I like living, so I wouldn't mind being incarnated again. This world has a suffering, but at least it's an interesting place, and I've found lots of joy here too, so I if I return here, I won't be entirely disappointed.
I'd prefer someplace that is closer to my vision of a world that "fits" me, though. Someplace with more deep forests, someplace where we get to do more co-creation and physical reality isn't quite so immutable. Someplace I'd be able to be more of who I am in spirit- more wild, more free. Not necessarily less responsibility, just different responsibility. My soul longs to wander in the mountains and tend to nature, but this world unfortunately demands an awful lot of time spent on things like grocery shopping, commuting to work, and such. I often long for a place more filled with the magic of experiencing life, in which people are more vibrant and less concerned with themselves... and in which there is a deep resonance of all with the Divine. Not necessarily a perfect world, or an easy world... but a very beautiful one. One in which we all could wander through the woods freely, dance in the starlight, care for one another without hatred and ignorance and violence, create myths around the fire, speak with deep kinship to animals and trees, create art in all we do and live as one with the Song of Creation. Not an unchanging world, or a world without work, or even a world without pain. But a world of freedom and beauty and passion. I guess I long for a place I could be more of myself and belong more with others, without the constant grief I feel at what we do to our earth and each other here and now.
I guess that'd be my "heaven." I have never wanted streets paved in gold, or mansions, or anything like that. I wouldn't mind such a place not being eternal, and I don't mind my own mortality. I like the excitement of having a timeline, though I wish it were quite a bit longer to allow me to experience more of this life, this world, the people around me. But I don't mind death, and if I'm right about myself, I'll just be reborn somewhere/time else anyway.
Nirvana always sounded peaceful, but not very exciting. I think, at least for now, I'd prefer just going 'round and 'round some more. I have far more I want to experience in this lifetime than I can possibly cram in.
As for the popular conceptions of heaven and hell- I don't buy into either one. I think the idea of paridisical or horrific realities is separate from the idea of union with or separation from the Divine. I have moments of heaven on earth, if heaven is union with the Divine/God. I do think that when I am freed from my bodily limitations, I'll be able to experience even further a union with God, but then my idea of God is not very anthropomorphic. I see heaven and hell more as states of being or consciousness- how much we bring ourselves into a union with the Divine, and our lives into a harmonic resonance with the flow of ultimate reality. It's difficult to describe, but hopefully you all catch my drift. Heaven and hell, in my opinion, are something we choose and co-create with the Divine in ourselves and our world. It's up to us how much we create heaven or hell on earth, and how much we create it in our hearts and souls. I don't think this changes after our death. We are then freed from our bodies, either to be in spirit/energy only for a while (or perhaps for some, forever) or to be put back into a new physical form, but what paths our souls choose to follow is still our own choice.