Lunch at Art Basel: The central courtyard thrums with activity. It is a time for sausage, oysters, ice cream, Champagne.

PHOTOS: ANDREW RUSSETH/ARTNEWS

The 49th edition of Art Basel is now in full swing, with some 300 exhibitors and countless collectors convening on Tuesday morning in the city’s convention center for the first day of action. (The fair opens to the public on Thursday.) As the premier marketplace for modern and contemporary art in the world, this is the show that dealers save their best work for, and so, even when you hit a bleak booth or something not to your taste, other delights await just a few steps over. The pace is unrelenting. Below are 45 highlights from the aisles—works or booths I would like to buy or steal or receive as presents—along with a couple other photos of the scene. Basel runs through Sunday, and our reporting will continue throughout the week.