It is actually it is difficult to choose upgrade for N95! As you know the potential of the device N95 it is always a challenge?
There are four options:
N97 - The goodness of Symbian with the touchscreen sweetness. big screen and widgets are also very good welcome to this device.
N97 mini: - This is just the little brother of the N97 with compactness and all the sweetness of its elder brother.
N86 :- It is the best chance to get an improvement to this device for 8.1MP camera. But it doesn't sports a Xenon flash , a major drawback of the device but it can be excused for the wide lence aperture of the camera which is an equivalent DSLR feature (For Wide angle shot).
and last but not least
N900:- This is best choice if you use your phone for browsing and connectivity applications. Itis a alrounder in this segment and even excells any other device in its range. And its touchscreen and firefox support and flash lite 10 support is the major advantages.
The drawbacks of this device is that maemo is a fresh platform , it'll take some time to get some applications available for the device.