Interesting question. Personally, I prefer the number of levels to be on the small end (10-20), and allow for some of the growth to be through equipment, so even if it's been a while since your last level, you can get a pick-up from that new belt or whatever.
I grew up on isometric CRPGs like Baldur's Gate, though, so I wonder how that colors my preferences. If I played JRPGs, would I prefer a higher (or no?) level cap?
In a typical Dragon Quest game, the level cap is 99, and by endgame you would realistically be around level 40 or so. (This applies to DQ3 through DQ8, which is a good portion of the series.)
Final Fantasy games typically take you to higher levels; in FF3, FF4, and FF6, level 60 or higher is typical for endgame. (FF5 is an oddball here, and the game is usually finished around level 40.)
Another thing is that, in many JRPGs, it won't ever be that long since your last level.
There's also the concept of secondary growth systems, as seen in Final Fantasy 5 and later, where there's something other than XP or Gil that you get from battles, and which allows you to learn various abilities; this is something you generally don't see in WRPGs.
On the other hand, there are a few older WRPGs (Wasteland 1, Wizardry 6-8) where you have levels, but your skills can improve with use without you having to level up, and that allows you to see improvement even if it's been a while since your last level.