I’ve read the manga version as well as watched the anime version. The anime version is an extended version with more characters involved. Here are some of my favourite scenes:
You don’t mess with Erza XD
So it turns out that the person who was rampaging around in the casino wasn’t Ellie but Erza.
Um… you got it wrong, Juvia.
I like the interactions between the Fairy Tail and Rave Master characters, and how they show how similar they are. The speaking slot machine was a weird idea, but all in all, I liked how it gave the opportunity for the Fairy Tail and Rave Masters to fight together. If you’re looking for something funny, I recommend that you watch this OVA.
Link to anime version: http://www.animeultima.tv/fairy-tail-x-rave-episode-1-english-subbed/
Manga version: http://www.mangahere.com/manga/fairy_tail_x_rave/