I'd say that Jonty Evans, Camilla Speirs, Sarah Ennis and Cathal Daniels are the ones to watch far.
Evans really had an excellent performance in Rio. Ennis and Speirs also had some eye-catching results lately. And, I mean, Camilla Speirs & Jiffy are just the ultimate crowd favourties. Cathal had a very promising 4* debut in Pau at the end of last season. His Badminton debut should be exciting.
Aoife Clark is also there, but she & Fernhill Adventure seem to be lacking some confidence across the country after some minor injury problems. They have apparently received 20 jumping penalties in XC in all three of their latest competitions.