Signed albums, signed polaroids, I also really adore the voice files and the same files! The videos too! I'd take any in my list over what was listed in the poll.
Signed merch :)
Agreeing with the rest of these comments. My faves are usually the signed albums (they are musical groups most of the time after all), and polaroids are unique, so I love those. And personally, I really treasure the cards/letters written by the members. Something written specifically for me by my beloved idol? Best thing ever. ;)
Signed poster, signed album, signed polaroids... I love autographed merch, feels special!
photocards and stickers!!! i love stickers!!!
A T-shirt or a bag with the group logo would be nice...or also a bracelet or a keychain with the goup logo as well...
Polaroid photos! I only have a photocard that resembles a polaroid.
the actual physical album cd? xD
Lightsticks as long as the group has one