Ditto going to a running store. And you'll want separate pairs for running & cross-training. Running shoes are built very differently from cross-trainers. When I started spending more money on my shoes (like >$50) my joints were grateful. I've been through several pairs of running shoes in the ~2 years I've been running, & you get what you pay for. My favorite so far are Brooks, they're great for a wide foot.
If you just HAD to get only 1 pair of shoes, I'd go with running shoes, just be aware that they will wear faster if you use them for running as well as other training, & running shoes should be replaced regularly depending on your mileage. I had less than 300 miles on my last pair of Brooks but I was using them for cross-training as well so I just replaced them with a slightly different model...what a difference the new ones make.
| NO EXCUSES, JUST RESULTS
| Next milestone - 256: 60 lbs lost2013:
still up from 1/1, but coming back down...2010:
50.4 lbs lost | 2011:
17 lbs lost | 2012:
1 lb gained
How I did it: http://stubbysticks.wordpress.com/weight-loss-summary-by-month/