Not only is the size of this collection massive--over 500 works, it is also very well-presented. From the beginning it brings you right into the proper state of mind for viewing Salvador Dali's works. Dali was clearly one messed up individual. He appears to me to have been obsessed with doing whatever he could to be different, just for difference's own sake. But this doesn't change the fact that he created some amazing pieces, displaying fascinating concepts.
The exhibition has three main thematic areas: Sensuality and Femininity, Religion and Mythology, and Dreams and Fantasy, the last of which is the largest. You can see the relation in the works in these collections, and this setup does facilitate viewing the pieces. Some of the most notable items in the collection include the painting "Spellbound", Dali's "Tarot Cards", many of his graphical interpretations of various literature, and several bronze works.
Somehow, I never knew Dali worked with anything but 2-dimensional media, but the gallery has many of his bronze sculptures, and I believe it was these that I most enjoyed looking at. There are over 40 of his sculptures displayed, both large and small. The famous Horse Saddled with Time, Snail and the Angel, and Space Elephant are all there, for instance. And, although I don't know if I'd really count it as 'sculpture', but they also have the Mae West Lips Sofa on display.
Finally, if you have thousands of pounds to burn, you can buy a real Dali work. Prices range from £500-4000 for graphics and £2000-16,000 for sculptures.
The gallery is open 10am-5:30pm. For more information about the museum, see
http://www.daliuniverse.com/, or call +44 (0)20 7620 2720. The nearest tube stations are Waterloo and Westminster.
The gallery is wheelchair accessible from the entrance on Queens Walk (in front of the London Eye).
The museum admission fee is covered by the London Pass.