I have attended the NCLCA conference (once) and NADE conferences (twice). Both have been very useful and productive. I haven’t been to CRLA. I’d say both NCLCA and NADE are equally good as far as the content of presentations, etc. The major differences I’ve noticed between the two are that NADE comes across as more of a corporate-efficient, more impersonal organization while NCLCA has more of a personal, small-time operation feel (there are pluses and minuses to each style here, of course); also, NADE’s attendees seem to be from institutions spread across the USA with perhaps a focus on the east coast, while NCLCA membership seems significantly weighted toward the midwest – which makes sense since they evolved from a regional midwest organization. I’d say either is worth your while, based upon timing and such.