Nowadays, you're considered a heel and a boor if you don't welcome your daughter's fiancee into the family with a complete set of the Talmud Bavli, Vilna edition. This can run several hundred dollars and as a gift its absurdly impractical. Your average twenty-something punk is usually not into learning and when he's ready to settle into a nice middle age Daf Yomi shiur to make friends and impress neighbors he'll probably use the Artscroll anyway. The rare son-in-law who actually does want to spend his time leaning over a Gemarah likely already has the books he needs or easy access to them and likely won't ever use most of the volumes in the complete set. I mean who learns Zevachim outside of a Daf Yomi aside from the rare scholar who, sorry, is probably not marrying your daughter. Besides, volumes from the fancy sets are much too heavy to shlep around and look best sitting on the shelf -which is of course the whole point of the exercise.
We Jews like to pretend we're scholars and we like to pretend our daughters are marrying scholars. It's why every ignoramus is supposed to give a learned sounding speech at his sheva brochos and why those same ignoramuses receive expensive books that ultimately end up as living room or study decorations that attempt to proclaim to all that their owner is a scholar, but in reality announce only that he has a father-in-law who follows convention.
When it's my turn, the son-in-law can have an IPad shas. It's lightweight, searchable, and costs about thirty bucks. Best of all it immediately let's the young man know that he shouldn't look to me for financial support. That, my friends, is called setting the tone from the outset. Try doing that with a leather bound shas.