187 (foundation), 239 (lid), 217 (crease).
if you use liquid foundation, i definitely recommend the 187. if i could only have one mac brush, it would be that one. i find that it applies my foundation more evenly and less streaky than regular foundation brushes like the 190. it also gives me more coverage with less product and is generally a quicker, more efficient application, imo. (note: i've never used mac's 190, just the same type of foundation brush from other brands. maybe the mac one is better, i dunno.. but regardless, i love my 187 <3)