Just for a bit of fun, I thought I'd ask around to see what people would recommend as my next lens. You can see the lenses I currently own below

I was going to get the 85mm ƒ/1.2L USM II, however I have been thinking lately that the 50mm might have me covered for a while, and I should get something drastically different to add more variety in my line-up.
Should I get a macro? Or Maybe a tilt-shift (If so, what focal length? I've read that the longer a tilt shift lens the more exaggerated the effect, however only the 17 and 24mm's are L series), Wait for the new 24-70? Or get something a bit longer 135 or 300mm prime?
Any suggestions are welcome! Budget is around $2,500

Go nuts! And thank you in advance!
Also worth noting that 300mm was one of my favourite lengths on film, and I'd love to have that focal length, however I don't think I'll be able to afford the ƒ/2.8 version, is the ƒ/4L still a good lens? Or is it aging now? How does it compare to the new 70-300? (despite the obvious lack of a stop)