make the rack public and post a link to the rack (copy and paste the url here) not to a jpg - no click through or infomatics on jpgs - they really help us help you as there are thousands of modules!
a delay would be useful - consider an fx aid xl - it'll add delays, more 'normal' reverbs, lofi, phasers etc - definitely good for all stated genres - make sure to get the xl it has more modulation inputs and better ergonomics than the standard version
a matrix mixer for mixing bits of modulation together to generate more interesting modulation - I like the doepfer (as it has full size knobs and space and is inexpensive) - but the instruo lion looks interesting
stackcables (or another passive mult) - for utilizing the matrix mixer and still having the original modulation available
a basic starter set of utilities - links, kinks and shades will add a lot for not that much cash - other modules that do similar things are available - wmd/ssf toolbox covers a lot of ground too
I'd want 50% of this size of a case to be modulation and utilities for manipulating it...
"some of the best base-level info to remember can be found in Jim's sigfile" @Lugia
Utility modules are the dull polish that makes the shiny modules actually shine!!!
sound sources < sound modifiers < modulation sources < utilities