Snapdragyn
Explorer
My preference would be for theme books. Some of my favorite 3.5 splats were the 'environment' series (Frostburn, Stormwrack, etc.) & the 'heroes' series (Heroes of Honor & the other one).
I do think trying to do both theme & class-focused books is NOT a good idea, at least from what I saw in 3.5. I played in several campaigns where it was 'core + Completes'. I never played in ONE campaign that was 'core + (any of the themes)', nor even an 'anything published by WotC'. The more lines they put out, the greater the chance a DM will exclude an entire set of books sitting on my crowded bookshelves.
WON'T SOMEONE THINK OF THE BOOKSHELVES?! *sob*
I do think trying to do both theme & class-focused books is NOT a good idea, at least from what I saw in 3.5. I played in several campaigns where it was 'core + Completes'. I never played in ONE campaign that was 'core + (any of the themes)', nor even an 'anything published by WotC'. The more lines they put out, the greater the chance a DM will exclude an entire set of books sitting on my crowded bookshelves.
WON'T SOMEONE THINK OF THE BOOKSHELVES?! *sob*