I use a DLink DGL-4500 Xtreme N Gaming Router. For me this works well as it has super fast ports, has many options and broadcasts dual bands for multiple wireless connections and I can easily set port priority on devices. This way my xbox or pc or whatever device I wish will get the highest bandwith without bottlenecking. Most decent routers have this feature but this one is quite easy to set up.
About firmware however. Please make sure you research the latest firmware BEFORE you install it on your device. 9 out of 10 times the instructions will tell you there is a firmware update you can perform right out of the box. Don't do it yet. Check the forums, listen to comments and be very careful before you install. First, if it aint broke, don't fix it! Meaning, if you have a solid connection with no drops or communication errors on your devices, just leave it alone. There may be a higher firmware version available for your device but it may be unstable or buggy for your setup. Also, in some cases once you do update to a higher version and find out it is unstable or buggy, you can not roll back to the previous more stable version. So now you are stuck with a buggy unstable connection dropping signal constantly. Further, once companies move on and stop supporting devices, you are left holding the bag as they will not provide you for a means to roll back or forward further for an escape. At this point you have to seek the community's help and hopefully someone will have a fix.
So always check the support forums for the particular device you are thinking about flashing the firmware before you do so. It can save you many a headache if you do.