Many good hotels in XMN, but my go-to is the Sheraton. Good location ( for me) , less than 15 minute 25-odd yuan ride to airport,
excellent lounge, and never missed a suite upgrade ( in 30+ stays).
If going as a first-time tourist, you may want to stay on Gulangyu, but the city is compact enough that you can stay anywhere and get around easily.
Sorry, never stayed overnight in KMG, only day transits so no recommendations.