I'll admit my roleplay ideas are strange and a bit perverse, but hey, maybe that's your thing to.

[b]Body Swap[/b]
 In this roleplay a young man finds himself swapping bodies with 
A) his girl next door neighbor
B) his slobbish sister 
C) his pregnant aunt 
D) his best friend's mother 

Or a mix of the above into something which also suits your tastes.   The appeal for me in this roleplay (aside from perverse gender-bending fun) is the comedic/semi-dramatic stories which can be shared. There doesn't need to be a reason for the swap, and if you prefer possession instead of a body swap that can be discussed too. 

The above are modern centric roleplays, I'm also interested in the more fantastical. 

A few ideas: 
A portal opens up and our characters step through (mine being male, yours whatever your preference) we find ourselves transported to a fantasy world (high or low fantasy) where we also have new bodies and lives. Roles I'm interested in:

A) A young princess 
B) A pregnant queen (and widower) 
C) A poor stable girl 

The fantasy RP can have all the danger of secret assassins and scheming relatives, and all the heart thumping romance and adventure you could shake a stick at.

Clarifications:

1) I want to play a male stuck as a female. 
2) I'm happy to play with males or females
3) I'm also open to ideas on the theme of possession and body swap
4) I'm fine with lewd roleplay, but I am looking for a literate partner and a good story.

5) I'll aim for 1-2 posts every 24 hours, hopefully more if possible.