1. Palpatine showed compassion and selflessness for a cause...the Sith. He helped bring to fruition Bane's long lost goal of conquering the galaxy and the Jeid, even though it was somewhat short lived. While most people, including me, will acknowledge that the Sith are bad, thus supporting their cause isn't in itself an admirable quality, the more abstract effort of supporting a cause still counts. Palpatine didn't have to help the Sith. When his master was dead, he could have done whatever he wanted.
Now you might argue that he only served the Sith so he could get as much power as he wanted (he was definitely power hungry). However, Palpatine took Vader as his apprentice. Why? Why take Vader as an apprentice? He didn't need Vader to do Order 66. He didn't need Vader to become Emperor. He needed Vader to continue the rule of two. If he died, he needed a successor. He also needed someone to keep him on his toes, to keep him sharp, to push him to continue to excel. And if he should grow weak, Vader would be there to kill him, just as proscribed by the rule of two. In that end, I believe Palpatine had a little bit of selflessness that did believe in the Sith teachings.
2. Palpatine was a very gifted speaker. He was able to sway Anaking Skywalker to his side, he was able to mobilize an entire galaxy to turn on the Jedi, and he was able lead an empire without them overthrowing him...until of course ROTJ, but it was a good run. Regardless, Palps had a gift for speeches. (point in case: Darth Plagueis )
3. Palpatine was also very insightful and perceptive. I remember when we first saw Palpatine and Luke talking with each other on the second Death Star.
Luke: Soon I'll be dead, and you with me.
The Emperor: [laughing] Perhaps you refer to the emminent attack of your rebel fleet? Yes, I assure you, we are quite safe from your friends here.
Luke: Your overconfidence is your weakness.
The Emperor: Your faith in your friends is yours.
And the Emperor was right. That one little line showed the Emperor was quick on his feet and not a dummy. He was very good at spotting weaknesses and opportunities.