Most acrylics dry very quickly, within minutes in a hot studio, but some brands are specially formulated to dry more slowly without having to add retarder medium. This is a list of different brands of acrylic paint, arranged by drying time.
Always remember though, environmental factors also influence the drying time of acrylic paint. If it's very hot and dry, or if there's a breeze (or draft from an air conditioner or fan), then the paint will dry faster. Working in a cooler or more humid location will slow drying. The surface you're working on has an impact too (paint dries faster on paper than on canvas because water is pulled from the paint into the paper as well as evaporating) as does the thickness of the paint (a thin layer or glaze will dry rapidly).
Acrylic Painting Drying Time:
Slow: Golden Open Acrylic, up to two days.
Slow or Fast: Atelier Interactive is in a category by itself, as the paint is formulated to dry by thickening not skinning over, and can be reactivated by spraying with water or unlocking medium.
Slowish: Winsor & Newton Acrylic, up to 30 minutes.
M Graham Acrylic
Fast ("Normal"): Most brands, including Golden (excluding Golden's Open Acrylics), Liquitex, Matisse, Sennelier, Daler-Rowney, Utrecht, Amsterdam, Maimeri, Tri-Art, Winsor & Newton Galeria, etc.
Fluid Acrylics and Acrylic Inks: Both these forms of acrylic paint dry fast.