JNUL digitized books
An early printing of the Mishnah, known as "Defus lo noda".
Tumat Yesharim, Venice 1622. Includes the first edition of Temim De'im. TD is an important collection of Provencal halakhah, and is the only source for many 12th century responsa.
The requisite Steinschneider book.
Talmud Yerushalmi on Kodashim, Szinervaralja (Romania) 1907-1909. See here and here and here.