Pokemon is one of the first three series I've ever played, and it's by far kept me the most interested. While I still like other games a lot, I just like Pokemon the most. I've explained before that its the large amount of cool creatures with many things to distinct them from one another. There's a lot of things to like, the only notable flaw I can think of is that the main series formula stays the same too much, resulting in games that are more similar to each other then they should be, along with a worse story. I still think Pokemon has more positives then negatives, and it's very doubtful that I'll ever lose interest.
The games just keep continuing to improve (although changing is an issue like I've said), and although I have mild concern for the future, I'm sure it'll be around for a long time.