My current combos are RY bridge with IT middle and mule neck, which I really like as the bridge can go from classic rock stuff to modern metal with a flavour I really dig, the middle is more for clean to midgain stuff, but gives a great single coil feel without being too radically different then the HBs. The neck is also great, bloody great clean tones and can go suprisingly high gain. Classic feel with insane versatility. I also use splits on this one, middle + outer coil and I love those too. The bridge split is amazing for clean strumming and the neck split shine when I want my neck lead sound to have a little more dirt and bite for a specific passage or something.
These combinations with this wiring offer a gigantic range of tones for as many styles.
Might try a MQ neck in place the the Mule sometime soon though as I will have one lying around.
Also have a Crawler set combined with a slowhand middle where it fits in the same way the IT does with the set above. It keeps with the general character of the HBs but delivers a distinct SC sound.
I also am about to order a Stockholm bridge supermassive neck combo to see how that goes.