I saw this in an old post that was similar in topic. The poster had asked about the "essential" books to purchase to get started in RM2. I was wondering what some favorites were from members of the forum, which may not be essential for running a session. Some of the guys I am introducing to RM2 asked me which books they should buy in order to prepare for gaming. While the essentials are great, I also included some "favorites" as well. Which for me... are my "essentials" in addition to the ones necessary for running a session.
Elemental Companion: My RM world is strictly Elementalism. There are no other magics in the world. With the thousands of spells to chose from, it's far more manageable to find some way to limit the deluge of information and lists to work with for a new player. When I first started playing RM, the group had already set up a strictly Elemental world and I've always loved it. This is by far my favorite book. Everything about the book was so well set up from the histories, to the planes, to the creatures, the examples throughout the book, the crit tables, and so on that I've just sat and read through it just to be lost in the Elemental world. It's purely enjoyable read and feels more like a story book than a Companion.
Heroes and Rogues: I was the only one in my group who bought this Companion and I was mocked for wasting my money. "Why can't you just make your own NPC's? Why do you need a book of NPC's?" I've pulled so much info from this book over so many dozens of sessions it's been a great book to have. An example of the basic Professions, with stats for various levels of NPC development, with items and a great story line to explain the history and the path each character took to get to that final level. I've made campaigns based off different NPC's from this book, using some or all of the background story. My daughter now has the Ghost Armor which is non-encumbering and protects as AT16. She loves it because it makes her look like she's wearing a ghost. It's her favorite item in the game. It's an excellent resource to pull an "emergency" level 7 monk, or level 10 ranger when the story line takes an unplanned twist.
Arms Companion: Just when you thought all of the possible options have been exhausted, Arms Companion comes out with a wealth of new options, items, charts, and info. Maybe I'm partially jaded since I've always preferred non-spell users, or maybe there's just sooooooooo much out there for the spell users, that it was nice to have one book dedicated to the hands-on characters.
Creatures and Treasures I: What can I say? It's the best of the three, IMHO. I love reading through this book and just dreaming up campaigns based on items that catch my eye. My daughter is 12 and she's started looking over C&T1 and planning out her own campaigns based on something that she would like to have.