SBUX is also very good at training their employees. They tend to be really chipper and genuinely seem to enjoy working there, which makes for a more pleasant consumer experience.
They have good quality cups and lids (unlike Tim Horton's where I resign myself to the fact that I'm going to burn myself when their cheapo lid malfunctions), and, as everyone else has said, the coffee may not be the best, but it definitely won't be the worst. And when you're craving a coffee there's nothing more disappointing than a hot cup of dishwater.