You're allowed to move up two sports, one mens, one womens, and the sport can not be FB or BB.
Which eligible to move up mens sport is most ready for a move up?
Swimming and Diving.
Sorry but Golf, Cross-Country, T&F, and Baseball just aren't there. I'm with 'star2city' on the thoughts of Golf and Baseball in DI.
Which eligible to move up womens sport is most ready for a move up?
That's a tougher call. The womens S&D team is (relatively) weaker than the mens. Soccer and Volleyball aren't there but could probably get there just as fast as S&D could.
Golf, CC, Track, Softball, and Tennis would take even more time.