Getting the right type and size battery for the job is probably more important than the brand, especially when you consider most familiar brand names are simply private labels on batteries actually made by one of the three major battery factories in the USA (Johnson Controls, East Penn or Exide). For RV house use (not engine cranking), you want a deep cycle type with enough amp-hour capacity so that you rarely discharge it to less than 50% of capacity. That will assure you a long battery life and plenty of power for your needs. And for those who aren't willing (or can't remember) to check the battery water level, an AGM or Gel type sealed battery is the best choice, despite the substantially higher price.
The Optima Blue Top mentioned in the first post is an example of an expensive battery that is optimized for engine starting rather than deep cycling, so not the first choice for RV use. The Yellowtop claims better deep cycle performance. The Blue Top is, however, an AGM design and those generally hold up pretty well.
The Lifeline and Trojan brand batteries are made by specialty battery manufacturers who design for deep cycle use in rugged environments. Their AGM sealed batteries are probably the premier choice for RV use, but they are very expensive. You probably get more value for the dollar with a generic flooded cell deep cycle designed for golf cart usage (6V, GC2 size), but you have to be religious about monitoring the water in the cells. These are available at prices in the $95-$125 range (depending on store and region) but it takes a minimum of two to produce 12v and the amp-hour capacity (225/pair) is probably more than some people will ever need. My second choice for those with minimal capacity needs is a single 12v, flooded cell, "trolling motor" battery, available at Walmarts and similar discount stores for around $70 for the Group 27 size. They should be good for 3-4 years of use provided you mind the water level in the cells.