The largest I've ever used: (only anal because I don't have a vag)
Girth: the head was 10" in circumference, and the shaft was 9" in circumference. I could only take in about 7" of its length.
Length: 13.5" insertable(can take in 11" - 12"), but the toy was thinner than the one mentioned above. This one was 8.5" in circumference.
The largest I've seen? Online? 6" in diameter.