Photography and the various trade-offs in choosing a camera is a pretty complex subject, but I'll say this:
Most modern digital cameras (compacts, bridges and SLRs) from the "big name" brands are capable of taking very nice photos - it's often the skill of the person wielding it that makes the difference. If you have a modern big-name camera, depending on your current level of ability, it may be worth investing in learning more about composition and how to use the camera rather than buying a new one. A fancy SLR will only make a big difference if you're already pretty good.
Having said that, there are a couple of things that differentiate cameras: low-light capability for night shots, zoom capability (specifically, being able to zoom out to wide angle is handy in cities to help with walking-backwards syndrome), the ability to take a polarising filter for bright conditions. If you had particular problems with these issues last time, you might want to check specs and reviews of cameras for these specific capabilities.