For with your 8-year old, almost anything by Studio Ghibli will be okay (see note about Monoke Hime below), although my favorite is Kiki's Delivery Service followed by My Neighbor Totoro.
Azumanga Daioh is another one that's okay for children, but is a little odd. Sort of slice of life, if you can get past the weirdness it is fabulous.
Aside from the utterly childish ones like Pokemon, most anime is designed so that adults can/will enjoy it too.
Stuff that might not be okay to watch with your 8 year old:
Tenchi Muyo is silly, Key the Metal Idol is beautiful, ditto Escaflowne. Neon Genesis, a lot of people watch, but that is really really odd. Child's Toy (Kodomo no Omocha) is about children, but deals more with relationships. Kare Kano and Ai Yori Aoshi are both romantic comedies as well, with older main characters than CT, KK has moments with an art style that can be hard to follow. Ranma 1/2 is sort of the candy of the anime world, it's fun to watch for awhile and then you get stuffed and sick of it, stop for a bit and then feel like watching it again. There is a *huge* amount of that series available. The Slayers' series are more action-adventurey.
On the more serious side of things, Monoke Hime has enough violence that you might want to watch it yourself before you let your son see it.
Anyway, I'll let someone else chime in with more ideas.