The word in the Greek translated "cheerful" is "hilaron," from which we get the English word "hilarious." However, because the word "hilarious" has connotations which are not in the Greek, it would not be good to translate the sentence as "God loves a hilarious giver." Nevertheless, the translation "cheerful giver" is weak. The sentence may be better translated: "God loves a jovial giver." We should give with more than a pleasant attitude and a smile. We should give with a laugh — even a belly laugh.
Moreover, we are called not only to give something to God but to give all — to be a grain of wheat which falls to the earth and dies (Jn 12:24). We must give God our bodies, minds, emotions, money, time, energy, work, sexuality, wills, etc.
We can laugh heartily and joyfully when we give our lives totally to the Lord because we know that God the Father has adopted us, Jesus has died for us, and the Holy Spirit has made our bodies His temple (1 Cor 6:19). After what God has done for us, the least we can do is to give Him everything and to enjoy the privilege of giving such a gift. Give all to the Lord with jovial laughter.