Close Encounters was the first indication that his movies were likely to morph into something less tight and visceral, with the special effects in the "Special Edition," the version I watched, ultimately proving less thrilling than the earlier, earthbound segments (just as Jaws succeeds by not showing the shark, it's the unseen and inexplicable that's most compelling here).
There's a brilliant sequence early on, for instance, where air traffic controllers crowd the shot - more and more heads joining the fray, staring intently at a radar display - as a pilot reports a strange phenomenon. Despite never leaving the cramped control room it's one of the film's strongest moments, making wonderful use of the frame and of radio-traffic sound effects (Orson Welles might have been proud). Another odd event, later, is filmed from within the cab of a pick-up truck and it's a sequence as eerie as anything involving motherships and gangly aliens.
Even though the film's later sequences are a touch overblown, there's still great pleasure to be mined from the panoply of film references, whether it's the old-fashioned slapstick of Richard Dreyfuss struggling with a rubbish collector, the nod to the concluding segments of Hitchcock's North by Northwest, or the more insular reference to the music from Jaws - as well as the various movies that play in the background at key moments. From my perspective, there was also the intrigue of wondering just why young Barry, the little boy so fascinated by with the lights in the sky, wanders around in a Boston University t-shirt; my employer doesn't routinely turn up in pop culture phenomena.