Comfort food garbs your tongue in luxurious velveteen knickerbockers of flavor, as opposed to discomfort food, which clings to the face like an overtight ascot. Today's Groupon soothes stomachs with half off breakfast, dinner, and more at Sugar Cafe in Union Square. Choose between two options:

• For $5, you get $10 worth of breakfast or lunch fare.
• For $10, you get $20 worth of brunch or dinner fare.

A 2010 Best of the BayList coffee-shop nominee, Sugar Cafe's daytime, caffeinated digs mellow into a moody lounge by night. Mornings buzz on fresh brews by Bicycle coffee, an organic and sustainable brand of South American beans. Lunch favorites skew from flavorful egg-salad sandwiches ($7.95) to the Mangia! salad, a toss up of salami, chickpeas, roasted red peppers, red onion, and kalamata olives ($8.25). Blow up inflatable brunch dates for plates such as pancakes fully loaded ($7.95) or stuffed french toast, aptly shoved with lemon cream cheese, fresh blueberries, whipped cream, and seasonal fruit ($7.50). After 5 p.m., Sugar switches gears, crawling into its less-than-dark hole with help from a fireplace seating area and very important conversations. Watch wall-projected movies as you nosh on house sliders ($10) or the vegetarian-friendly truffle mac 'n' cheese ($8). Stay late to sip an array of freshly shaken martinis beneath the ethereal, purple glow, which attracts a cultural crosscut of art students, doctors, entrepreneurs, and people eaters.

Reviews

Zagat rated Sugar Cafe's appeal, décor, and service very good to excellent. More than 475 Yelpers give the cafe a 3.5-star average and Citysearchers give it an average of 4.5 stars.

• A cafe “by day” where coffee fans can “grab a couch” and a cookie or other treats, this Downtowner transforms into a “lounge by night” when “movies playing” in the background “lend an air of mystery” to the “modern-looking” space; sweeties suggest “getting a spot by the fire” as an “incredibly romantic” roost for a “quiet conversation” over one of the “unique cocktails.” – Zagat