Happy

доволен

dovolen

(content (to do something); having no objection (to something))

ра́достен

rádosten

(contented, joyous)

уда́чен

udáčen

(apt, felicitous, fortunate, propitious)

удачен

udačen

(fortunate, lucky)

щастли́в

štastlív

(contented, joyous)