I prefer the Fantasy Tower. We have a lot of purchases sent back to the hotel, so it's nice to be close to the bell desk. You also have the shops right there in that tower & it's closest to most of the restaurants.
The Frontier Tower is just too far for my taste. I know in the real scope of things, the distance isn't that much further. But, when you've pushed your park touring to the limit for 12 hours in a day, that extra 100 yards can feel like a mile. Especially on day 6 or 7.
The Adventure Tower is technically closest to DD & the monorail & definitely the tower that I hear most people recommend. I've only stayed there once, this past July & I really didn't like it. A lot of that was probably due to not having a great room. So, we didn't enjoy our time there, but as I said, a lot of people seem to like it.
I hope you're able to get your request for whichever you choose!