・・・。
Honestly, Keiko's somehow both adorable and a little infuriating...
Literal
Jeez Keiko-[affectionate-ちゃん] [topic-って] cute [nominalizer-んだか] annoyingly-cute [nominalizer-んだか]...
ったく is the contracted/spoken form of まったく 'honestly / really / jeez,' a common expression of exasperation. ~んだか~んだか is a set pattern '(don't know) whether X or Y,' where both options are offered as possible characterizations and the speaker throws up their hands. 小憎らしい (literally 'slightly hateful') is the interesting case of a negative adjective that has softened into a near-compliment — 'annoyingly cute / adorably infuriating,' applied affectionately.