Well, there's Anju in Karin
There's Hagino in Canvas 2.
There's Shinobu in Love Hina.
And you could try Higurashi for loli design overkill (stress the kill there).
Haruhi called Mikuru loli with big breasts, and if God says it is so, it has to be
, but Suzumiya Haruhi no Yuutsu has already been suggested. Kyon's imouto makes brief appearances, but she's the famous loli-in-a-bag, can't miss that.
Aruru from Utawarerumono (damn, it got licensed! eh... I mean hurray
)
Sakura from DaCapo (you could also count Aisia there, from DaCapo Second Season).
Sakura and friends from CardCaptor Sakura (duh
)
I think Multi from To Heart can fill the loli purpose.
In Bleach various loli types make an appearance like Ururu, and Ririn(only in the filler arc, that one). Some people count Rukia as loli type, although she just has the petite appearance loli factor, her behaviour is not even near loli
Hecate in Shakugan no Shana (ok, Shana's the star and Hecate only makes a brief appearance in the last episodes, BUT... it's Hecate you know
)
Chii from Chobits has the ultimate loli behaviour factor, although her body is more or less fully developed.
You could also try Mahoraba, there are one or two loli characters there, and the designs are cute.
If I remember anything else, I'll post
Hail the Loli Grail
