RFF/Forearm phallo is considered to be the best option in terms of post-operative sensation. For folks who care about being fully sensate, it is the "gold standard".
ALT/thigh phallo is a close second in terms of sensation, but is not an appropriate option for folks above a certain body fat percentage. The bonus here is a more concealable donor site. I have seen more guys having complications from ALT than RFF related to necrosis and flap failure.
MLD/back phallo is the third most popular. It uses a different kind of nerve, so the sensation is different. It is arguably the most concealable of the three major flaps. Downsides are the different sensation, and the need for 3 stages at a minimum without any implants.
Ab and groin flap offer little sensation beyond the base and have largely fallen out of popularity for that reason. Aesthetically, they look decent and the donor sites are very concealable.
I know nothing about fibula flap, but it is also an option.
It really all comes down to what you're looking for. I can generalize about why choose which ones, but if certain end results are important or unimportant to you, that can easily knock some options off the list.
