What book to buy?

[superninja109]

..Deleted..

[Waterdeep Merch]

If your players are already more or less settled on their paths, Volo's (and Mordenkainen's) are more likely to help you with their focus on monsters and their behaviors. Even if you homebrew extensively, just having easy access to a few gribblies for when you don't have time is great, as is using them for a solid basis. I personally use the section on generic NPC's more than every other non-core book combined during my games.

It's a really overlooked book, mostly because it does very little for players and thus isn't useful for most of the market.

ADDENDUM: Tome of Beasts is a nifty third party book if you're interested in getting a ton of more exotic monsters. There's a lot there which can be useful for Eberron games.

[Kane0]

If you’re worried more about DMing a homebrew campaign then Volos or Mords would likely find more use for you.
Xans and Tashas both feature more of a mix of player and DM options so your players are more likely to have a copy you can borrow.
Published adventures would probably be lowest on the list

[Ertwin]

If you want to have fleshed out factions, Guildmaster's Guide to Ravnica is a pretty good source with the eponymous guilds which I believe can be easily refluffed.

Was it Tasha's or Ravnica that also had excellent puzzle building for DMs? I forget.

[5eNeedsDarksun]

Of the Campaign books we've played the one that would offer the most to someone wanting to use it for a Campaign Setting would be Out of the Abyss, which has tons for different underdark regions.

[MrStabby]

Xanathars... is ok for a DM.

It has some of my favourite content (complex traps) but this is pretty much available from the UA anyway. With downtime activities and done magic items as well it has something for DMs.

For players who have picked and set their characters Xanathars still has some spell options that players might like.

Tasha's... is an odd mix. My plan had been to wait and see how people found some of the optional content before using it, however it seems to have engendered strong opinions based on feelings rather than experience of actually using it so I dont how how much I could trust feedback anyway. First thoughts are that a lot of the options are underwhelming in Tasha's - not underpowered, just under-fun. This is a matter of taste though, but it might also reflect that the design space is a bit more crowded. Obviously this is very much down to player taste though and is not really an overarching objective judgement.

Volo's is good at what it is. Actually, it's great for what it is... because it is so focussed on, well, monsters. If your DM problems can be solved by a monster stat block and some fluff, then it's great. Else it wont really help so much. Mordenkeinen's is somewhat similar.

[MoiMagnus]

Xanathar and Tasha have both content that are useful to DMs.
e.g I've had some fun with the Xanathar's set of tables that allows you to generate the past experiences of a character and Tasha's sidekicks look promising for creating PC-like NPCs but without the complexity of a PC class.

[NRSASD]

Volo’s is an excellent buy. Mostly mid-level monsters, but all of them are very solidly designed and a lot of them have fun, unique abilities.

Mordenkainen’s was a little meh for me. Decent stuff and good for rounding out the fiendish roster, but a lot of the monsters were templated versions of monster manual critters (here’s 15 kinds of Drow, etc.). Most of the genuinely new monsters were extraplanar and suitable for only high level play. Good but not as good as Volo’s, for me.

Tome of Beasts is an excellent concept, being 500ish unique monsters. With so many, there’s a lot of good, weird, and just plain unusable monsters throughout it. It’s from a specific campaign setting though it has been tweaked to make it easy to be repurposed. I’ve used maybe 20 of them over the years. Glad I bought it, but it takes a bit of work to find the monsters that are worth your time.

[2D8HP]

For "splat" The Sword Coast Adventurer's Guide has the "Swashbuckler" which is my favorite non-PHB subclass (Xanathar's has a slightly weaker version), Mordenkainen’s was an interesting read for campaign ideas (Elves are very alien), and Volo's had good stuff on Hags and Hobgoblins, but for more player options (beyond races) your choice is mostly between Tasha's and Xanathar's and for that I'd give a slight edge to Xanathar's, but the "DM Tools" in Tasha's are a bit better, but it's really close, frankly I'd go by artwork, and the "alt-cover" of Tasha's is gorgeous!

For published adventures, the licensed third-party 5e revision of "Into the Unknown" and "Keep on the Borderlands" Into the Borderlands (https://dnd.wizards.com/products/tabletop-games/rpg-products/borderlands)
is my top pick by far, and I would choose it over any "lore" or "splat" book, after that work it's:

Ghosts of Saltmarsh >

Tomb of Annihilation >

Tales from the Yawning Portal

[MaxWilson]

Since you already have Eberron/Rising from the Last War, I'd vote for Volo's, then Xanathar, then Mordenkainen.

Although if you liked Rising From the Last War as much as I did and you're open to content created by Eberron's creator but not paid for by WotC, you should check out Exploring Eberron: https://www.dmsguild.com/m/product/315887 It's excellent IMO, even if you're not running an Eberron campaign. I like EE's version of Slaads and the githyanki/githzerai/mind flayer wars more than the standard version, for example. One of the subclassed (Forged Circle Druid) is arguably overtuned but not as badly as the Twilight Cleric in Tasha's or even the Shepherd Druid in Xanathar's, and overall the subclasses/feats/items are well-balanced. Good book.