i was always the aunt that got the "interesting" gifts..... i didn't worry about the latest fad or toy. i am always drawn to the nature company stores, science museum store, aquarium stores, etc.
both my nieces and nephews like anything to do with nature, animals, never seem to outgrow cool stuffed animals, fake spiders and bugs, kits to collect bugs and things, books are always a great idea, old fashioned toys like slinky and etch a sketch, art supplies.
if you can find "giant microbes" anywhere, they were a big hit with my nieces and nephews last year. they're all between about 8 and 12. here's a link; you can order on line:
http://www.giantmicrobes.com/ i can tell you they're not really into clothes (even the girls) or things for their rooms (like lamps, etc). at least that's my family.
my family was always "afraid" that the kids wouldn't like our gifts. but usually our gifts were some of their favorites.
sue