Here are some places I've been interested in applying for internships in the future are:
Warner Brothers Animation: This company creates some of the most developed TV cartoons on basic cable. They cover such a wide spectrum of shows from superhero cartoons to Looney Toons. Throughout their long run, Warner Brothers Animation has set the standard of TV cartoon excellence.
Cartoon Network Studios: This studio is directly connected with Turner Broadcasting so its constantly making work directly to television. Cartoon Network has become one of the biggest networks for airing animation and offers many shows and departments to step into. It has been a consistent network at offering quality programming with a variety of styles and for a variety of ages.
Frederator Studios: Still relatively young but full of energy, Frederator has brought about many Cartoon Network and Nickelodeon classics into motion. The company looks very open and welcoming to new ideas and interns. Its fresh and current styles make whatever Frederator creates trendy and entertaining.
Disney: Disney has been the training ground for many great animators and continues to succeed in the movie and television industry. It has a very stable financial situation and would provide thorough training of skills and equipment. It would be a chance to be a part of the longest running and most successful animation studio ever made.