I have heard from more than one person that the most outgoing front in general is the mpimbwe (tanz.). I have both mpimbwe and burundi and can tell you its true in my case. My mpimbwe babies will let me hand feed them and the burundi will like to look at me but not let me touch them and will hide if i put my hand in the tank. Here are some pics of both of the types of fish, burundi and mpimbwe, keep in mind these are all babies ,not adults.
Mpimbwe (1 inch babies)
Here is a pic that shows my larger burundi fronts;
Here is a link to a video of my mpimbwe letting me hand feed them, the burundi never would do that and will hide when i put my hand in the tank:
Here is a pic of my burundi before they were in a tank with black sand and black background, i highly recommend the black sand and background, compare to the ones above where they appear so blue, big difference.
Burundi can look nice, my mpimbwe are F1 bought from a breeder but these burundi are petco burundi and nice looking in my opinion. Just avoid any with mooning or split stripes. They should have clean crisp defined stripes both black and white.