I'd be all over the 91 x Bubba, TK x Bubba, OG's x Bubba. Trainwreck x Bubba would be a good one, Cookies, Panama, I'm sure there is gold in everyone of them to be honest. If it were me I'd be lookin for the hybrids where the mom was on the lanky side and needs beefing up, that's where the Original Bubba shines in hybrids is making stronger/stocky stems and rock hard nugs that are iced out.
Cheese and Urkle were great when I made those, keepers in both lines for sure, there's a Cheese x Bubba keeper around here named the Cheddar, she's iced out like never before, everyone prefers her over the Cheese. Some nice ones in the F-Cut x Bubba also, that's why I'm sure the TK, SVF,Ghost, Tahoe will be winners.
Be interesting to see how the BT Bubba is crossed back, I personally liked her better then the Original. A guy can find many of keepers in Original Bubba S1's.