Ghorpm: Old RPG games that are very long due to constant battles with countless mobs, especially if it's in form of random encounters. I can't play games like that anymore so while I loved Wizardry series back then and I'll keep great memories it belongs to the past.
It's worth noting that what you refer to as random encounters I find preferable to the most common alternative; namely visible enemies moving in real time.
One problem is that it leads to situations where I get attacked before being able to open the menu to check my condition and heal. That situation never happens with typical implementations of random invisible encounters, where it is only possible to get attacked when moving.
The other problem I have is that it turns the game into an action game when trying to avoid encounters, which I consider unacceptable in a game that tries to be an RPG.
Also, in some games (the SaGa 3 remake, for example), visible encounters are actually worse than random encounters would be. In SaGa 3, for example, late game enemies move faster than you, making it impossible to avoid encounters without stopping time, which is a limited-use ability. As a result, you still have the issue of being unable to avoid encounters (hence not having the supposed advantage of the "visible enemies that move in real-time" system), but you also have the disadvantages of the system that I listed above, leading to the worst of both worlds.
If you want to implement visible enemies in an RPG, I suggest taking Lufia 2's approach, where enemies only move when you do; this keeps the game from turning into an action game.
snowkatt: i got some bad news about that thing though
its stand alone you cant add or buy more games
missed oppertunity there
Oddly enough, this lack of capability may be what makes me ethically OK with buying it; because you can't add games, there can be no DRM to prevent you from copying the games to another mini-NES. Also, this means that you don't need an Internet connection to play the games.
(Note that I am still thinking about how the mini-NES interacts with my "no DRM on digital downloads" policy, but it may pass precisely because it is not a digital download and does not offer the capability to acquire digital downloads.)