My favorite repeat spot is the Smoky Mountains of Tennessee and North Carolina. It's less than a 5 hour drive from where I live, lodging is cheap (3 bed, 3 bath delux townhouse for less than $100 a night? can't beat that!), and hiking in the national park is free and beautiful.
My favorite vacation of all time was to Granby, Colorado when I was 16. My grandma took me out to a "dude" ranch for a week, and we travelled by Amtrak. I rafted the Colorado river, rode my horse every day, won second place in a barrel racing competition in a rodeo, and got to visit Rocky Mountains NP every day (on horseback). The western National Parks are something I really want to take my own kids to someday.
Is it obvious that I would take the mountains over the beach any day of the year?