As someone who really loves music, I was nervous about deciding who to hire for my reception music: a DJ or a live band.
There are benefits and drawbacks to both, so it's critical to shop wisely and check references. A DJ is typically less expensive than a live band and can offer a wider range of music that will please guests of all ages. One friend of mine hired a DJ who was great at getting the crowd excited. He even managed to get my friend's mother-in-law, who never dances, out on the dance floor! However, if the DJ isn't up to par, it can really ruin the mood of the reception.
A band offers a more full-on experience for the guests than a DJ does. Watching the band can give non-dancers something to do. A good band is more likely than most DJs to read the crowd and improvise when necessary, which is a bonus. But the variety of songs the band knows may be limited compared to the extensive catalog a DJ has on hand.
My best friend and her fiancé had heard their reception band playing at a bar and fell in love with their unique style. It turned out that that the group had some experience playing at weddings and the couple was very pleased with their performance. I was in that wedding, and I can confirm that they really rocked the house!
In the end, my husband and I ended up going with a DJ, which turned out to be the right decision for our wedding. She fit our budget, read the crowd well, and even requested and used our list of must-play and must-not-play songs.