UPDATE: I've picked up a huge load of supplements for high fantasy, high magic settings and wanted to share my findings. My original inquiry saved at the bottom of this post with my findings being posted below with the most useful at the top. All inclusive means it's a complete overhaul to the BRB for a fantasy setting containing Character Generation, Magic, Combat, Equipment, Spot Rules, Creatures, and in some cases Settings:
BRB: Well, you wouldn't be reading this if you weren't a BRP core book holder would you? For obvious reasons, It's a great idea to pick this up first!
Classic Fantasy: (All inclusive) Pick this ASAP if you're running a fantasy campaign. It's got a magic expansion, some rules and spell adjustments, and great overall content. It also contains rules for turning BRP more like D&D without levels. It's a bit more broad with little setting help but that's also what makes it great. You can plug something from this book into any fantasy setting!
Michael Moorcock's Elric!: (All inclusive) This book is fantastic. The BRB contains the sorcery system found in Elric! but Elric! expands everything about demons, binding elementals, and some great darker fantasy setting information as well as a great "good vs. evil" backbone that drives lots of high fantasy settings. If you don't like the sorcery rules or darker settings, put a bit lower on your buy list.
Runequest 6th Ed: (All inclusive) I feel this is a really good book. Like Classic Fantasy it contains adjustments to all aspects of the game but unlike Classic Fantasy I find it less modular. The rules are meant to be used together. Great new magic options, combat styles, and includes some setting options Classic Fantasy intentionally ignores.
The Green: (All inclusive) I have not purchased the main book yet but the Venturer's Guide supplements the existing BRB magic systems wonderfully. I can't imagine that The Green brings any less amazing adjustments / additions, plus it adds a highly regarded setting. I wouldn't pass on this one if you enjoy the magic presented in the BRB and Classic Fantasy.
The Bronze Grimoire: This is an Elric! supplement that expands upon sorcery immensely. You don't need the Elric! main book to find it useful as the entire base sorcery system is included in the BRB. Elric! just provides more setting and summoning / binding information. Again, if you don't really enjoy the Sorcery system put this a bit lower on your to buy list.
Unknown East: This is another Elric! supplement but this time the focus is on a more eastern setting. The main reason to buy this is the free form magic system. If none of the BRB power systems really inspire you this one should. If you're looking for something far from the BRP norm, put this very high on your to buy list.
BRP Witchcraft: This is actually one of my favorite fantasy BRP additions, but I put it at the bottom as it's very narrow in scope. If you want hermetic magic, stereotypical witches, or divine aligned (white and black) magic then this is absolutely the book for you. It adds some great adjustments to casters that make them INCREDIBLY fun to role play and with many more options at the cost of less raw power. It gives different options for achieving your goals like killing targets slowly with diseases instead of fireballs and ways to pervert, subvert, and convert society to your whims even when playing a white aligned warlock or witch. It's just a great supplement, pick it up.
The Magic Book: This is basically a copy of the RQ3 magic rules and you'd probably be better served finding a copy of the entire RQ3 ruleset. RQ6 does everything this book tries to do only slightly better but if RQ6 is too expensive for you then this could be useful. I find using them side by side to be useful as RQ3 magic was more restrictive but could be more powerful. Having a copy of both allows me to pick and choose parts of the systems I enjoy.
Note: Magic World is coming out in 2013 as well as a supplement named Advanced Sorcery. These should cover most of Elric! and the Bronze Grimoire, but in a more colorful high fantasy setting instead of the dark setting of Elric!. It may be worth waiting for Magic World to come out and I'll update this post as I acquire Magic World and a few other books suggested in the thread.
BRP's magic system has left a little to be desired for my current campaign. I'm doing a magic / divine heavy fantasy campaign. Since Chaosium is having a huge sale I was wondering which supplements would be worth picking up.
I'm looking for:
Magic system adjustments
I heard bad things about brp witchcraft, basic magic, and the magic book. They are $5 right now (pdfs) so are they still worth picking up for that cheap? Why are they so bad? Would it be better to wait for magic world and the other supplement book (those look GREAT)
Creature / NPC expansion
Is basic creatures worth picking up? Are there any other type of monster manual type books that would be good for a high fantasy campaign?
Magic item additions
I'd like a good list of some magic items I could use in my campaign. Magic weapons, amulets, the like. Any suggestions?
General good fantasy books
Is Classic fantasy worth picking up? Also, although they may not be available from Chaosium, would a core setting book like Runequest be good to pick up, read, and adapt to my campaign?
Thanks for your time.