To be blunt, the Kree and the Skrull empires are both pretty nasty in the comics. Both of them have posed threats to Earth which is in a strategically important position between their empires. But there are good individual characters from both and it's the war that they have been fighting for thousands of years with the Kree that have made the Skrull what they are today. They were much nicer when they first encountered the Kree.
The Skrulls reached planet Hala, home to the barbaric race of the Kree (Who have appeared in the Marvel Cinematic Universe in Guardians of the Galaxy – Ronan the Destroyer is Kree), and the more peaceful Cotati. The Skrulls devised a contest between the two races to see which would represent the planet of Hala.
A group from each race was given a year of supplies and taken to two separate planetoids. The group at the end of the year that had developed a better society would then be deemed most worthy to represent Hala in the Skrulls’ list of favorite civilizations.
The Kree had been stationed on Earth’s moon and built a city. Meanwhile, the Cotati had created a beautiful park. Realizing that they were not going to win, the Kree killed all the Cotati, effectively becoming the race that would represent Hala. The Skrulls were disgusted by this development and decreed that Hala would forever be banned from their circle of ideal worlds. Displeased with that decision, the Kree murdered the Skrulls, took their ship, and developed their technology.
/Film, A Brief Comic Book History of the Skrulls, The Kree-Skrull War
While Lyja was originally a Skrull agent out to mess with the Fantastic Four she fell in love with Johnny Storm
Princess Anelle attempted to end the Kree-Skrull war by having a child with Captain Mar-Vell who became Hulkling of the Young Avengers.
Xavin, a later member of the Runaways.
Ethan Edwards, one of Marvel's many Superman parodies.