Sounds like you are going between the 13th and 20th when the PGA tournment is there. One thing to consider is going to the tournment itself (all the top pros are usually there including T. Woods)
As to the other courses:
1. Osprey is by far the best course on site (out of all of them including Palm and Magnolia). It has the most memorable holes and the last three holes are three of the best finishing holes you will ever see. Only downside is that it is most difficult course there (although not overwhelming) particularly for some holes where you need to carry water (such as 200 yards on the par 3 17, and 220 yards on the par 4 14th if you want a shot of actually reaching the green in two; note both of those holes have bail out options). Nevertheless, if you shoot in the low 90's or lower, this is not a course to miss.
2. Eagle Pines is the easiest Pete Dye course in existence. However, don't overestimate that statement; Pete Dye usually designs courses that are impossible to play; this one is very playable for most handicap levels as long as they choose the right tee. For example, it is the shortest course on site, causing some who play in the mid 80's or higher to choose the back tees, which usually results in their having a disastrous round. This is a lot of "target" golf with long waste areas or often water running along the edge of the fairways and lots of trouble around the greens. Very pretty course and thre sister course to the Osprey.
3. Lake Buena Vista runs through the Old Key West resort and is the easiest 18 hole course on site (but also don't overestimate that statement as none of the courses is either overly easy or overly difficult). It has a number of interesting holes including an island green par 3 and is kept in excellent condition as are all the courses).
