I'd love for a show to take us back to Mirinoi where a team of Rangers protects the new Earth colony... that would be pretty darn awesomesauce. Even if they make no mentions of Lost Galaxy just the name dropping would be enough and it would make for a sweet setting.
Hmm, perhaps a certain band of space pirates can make reference to it while on the lamb from their pursuers or something...
Not sure if it got brought up in the Gokaiger adaptation thread yet, but doing something resembling the Great Ranger War would bring up questions on which bits count as continuity and which don't.
Up to some of the character-centered one, Kendrix's "Double Duty" and Kai's "Blue Crush". Kinda stock stuff really, with "Princess and the Pauper" and "Babysitting/Romance" eps, respectively. Also... Rollerblading. In. SPAAAACE!