All of the commentaries of the great exegete Shadal are now online:
1. Commentary on the Torah (here) (Note: censored editon. For Devarim we have Shadal in the back of Nesivot Shalom uncensored.)
2. Commentary to Yeshaya (here)
3. Commentary on the rest of the prophets (here)
4. Commentary to two(?) chapters of Tehlim (49 and 51)
5. Commentary on Targum Onkelos (here) - also thanks to S.
Of his other Seforim I will only mention his Yesodei Torah and his letters - search for Igrot Shadal (Thanks to S.)
(A poem from Yeleg - however much I might dislike the man, he did know how to write)