1. X发烧友
发烧友 [fā shāo yǒu]
对某项事业或活动非常迷恋专注的人;狂热的爱好者。
fancier; zealot; enthusiastic fan
2. X迷
迷 [mí]
沉醉于某一事物的人。
fan; enthusiast; fiend; maniac:
a chess enthusiast;
棋迷
a movie fan; a film fiend;
影迷
I personally thnik that 发烧友 is a stronger word.
A 体育迷 enjoys sports while a 体育发烧友 would like to do much more things for his sports, like buying a complete set of top-tier equipment.