Hanuman Chalisa is hindi poem written by Mahakavi Goswami Tulsidas in the sixteenth century in praise of Lord Hanuman. It is very popular among a lot of modern hindus and is generally recited on Tuesdays (considered a holy day for devotees of Lord Hanuman).
Ganesh Chalisa is a popular chalisa (long prayer/ hymn) sung in the praise and devotion of Lord Ganesha, esp. during the inauguration or start of something new.