BIRTHDAYS.....?!

When my friends birthdays are round the corner i will have headaches, i don't know what to get for them, then will ask them this "What do you want for you birthday"? They will answer me this "i don't know ". I know birthday present are meant to have surprise but i don't want to buy something that is useless and unpractical to them, i want to get something they like and practical to them. When i say practical means useful to him or her. Hey people out there can give me some tips on my friend's coming birthday he is a gaming freak!