IM (Instant Messaging tool), which one do you use?

I just saw on cnBeta the news that the number of Tencent QQ users online simultaneously has surpassed 30 million! As a domestically produced software, this is indeed an impressive achievement. Regardless of whether their data is accurate or not, it's a milestone. It's reported that the number of Tencent QQ users online simultaneously today has already broken through the 30 million mark, reaching up to 30,242,566 people. The internal team at Tencent is preparing for a grand celebration to commemorate this historic moment, and Tencent may also hold a grand press conference. The 30 million mark signifies that Tencent has entered a new phase of development after surpassing 20 million, developing and growing even more rapidly. At the same time, we can see the following data. According to Nielsen Internet Research, as of June 2006, the number of American users for the three major IM services were: AIM 47.2 million, MSN/Windows Live Messenger 28 million; Yahoo Messenger 22.5 million. According to data released by comScore Networks, MSN/Windows Live Messenger has 204 million users globally, and Yahoo Messenger has 78 million. Among the aforementioned IMs, I've used all of them except AIM. I often used QQ when I was in high school, but basically abandoned QQ when I got to college. Now, I mainly use MSN and GTALK. I'd like to simply summarize my usage experience.