I have used artificial vaginas before, still have a silicone one in my closet somewhere...
Something that you can 'mount' to simulate sex always floats my boat. Otherwise I have to use pillows to hold the dang thing in place, and it is purple or something like that, feel like I'm f*cking a martian...
Also, maybe instead of an open end that gets messy at the end if you know what I mean; something to catch it all? Sorry if that's gross...