The Forks* (easily my favourite hangout in the city and a great place to show friends from out of town - the new outdoor portion of The Common is so damn good), Osborne Village, The Exchange District... Three places off the top of my head that have improved significantly in the last 10-15 years and each has something to offer for just about everyone (arts, entertainment, dining/drinking, shopping, etc.).
Ethnic restaurants of almost every variety in just about every area of the city, as well as the explosion of craft breweries/brewpubs (OGC is my personal favourite - amazing menu and brews)... For anyone to claim Winnipeg hasn't changed, much less for the better, is simply being wilfully ignorant and/or unreasonable in their assessment.
Put in the time to look; it's pretty easy to find whatever tickles your fancy.
* if you haven't checked out CMHR, I highly recommend it - the museum itself is pretty incredible and ERA Bistro is absolutely excellent.