I see I get it. So those Dragon Slayer can eat elements? I want to see one of those Fairy tale characters eating Whitebeard (quake).
Also I agree with NoLimit, Enel's fruit was the most impressive/awesome one.
Dragonslayer can it "their" element (they cannot it something they made by themselves) to recover and are able to use their element to attack. For example the main character Natsu uses flames to attack, can't be hurt with them and likes to eat flames.
I can only recommend reading it, I think it's worth it.
Which fruit I'd choose? Mhh maybe the door door fruits, mr. 2' fruit, Absalom's fruit, Marco's fruit or a logia (preferable Ace's or Enel's) (note: there is no particiular order).
I'd choose the door door fruit because it could be quite nice for transporting things or for being transported. Mr. 2's fruit would lead to very funny moments I guess. I could even work as a professional imitator xD. Being invisible doesn't sound bad and being (nearly?) invincible neither (and being a phoenix would be cool

). The reason for a logia doesn't need to be explained any further.