Polish is awash with words that are playful, and—to me, since I'm an English speaker—sound rather silly.
Dziki (Wild): I swear I can say this all day every day. I sometimes repeat it end on end until someone tells me to hush.
Spalony (Burnt): Rhymes with baloney. Any word that rhymes with baloney is sure to be a hit with me.
Akuku (Peek-a-boo): Even though it's childish and something to say to babies and little kids, it's still a joy to yell.
Ponimayo/Ponyatno (I understand/Obviously): Actually, this is Russian (a language that I've only recently admitted to being more beautiful than Polish.) I heard it from Cheburashka, and the way he says it just kills me.
Pan Twardowski (Mr. Strong): It only took me four years to say, but I finally got it down pat.
Dzwon (Ring (as in a bell)): Mostly because it's in "Hej Sokoly."
As my vocabulary grows, I'm sure I'll discover new words that I can randomly place in sentences for the hell of it (plus say without need or reason.)