The most popular are Dicor and ProFlex. What you don't want to use is a silicon sealant. Silicon is wonderful stuff, but, silicon migrates (the actual silicon component) and is near impossible to remove. The result? If you later need to do a repair and re-seal*, it will be almost imposible to get a new layer of sealant to "stick" due to the silicon (microscopic particles) left from the original silicon sealant. Butyl rubber caulk is a much better choice if you don't want to use one of the "RV specific" caulks/sealants. EternaBond also makes some very good "tape" type sealants used as a base sealant for trim, fittings, sealing tears, etc.
If you've ever tried to "re-seal" a bathtub or a window and found it near impossible to get another good seal that will stay for more than a month, the original sealant was probably silicon
I don't use silicon caulks/sealants for anything. Latex - yes; Butyl Rubber - yes, Polyurethane - yes, but, Silicon? Never.