I used to enjoy JRPGs a great deal, ever since I played http://en.wikipedia.org/wiki/Phantasy_Star_(video_game) on the Sega Master System. Great JRPGs continued to be released and were at it's height about a decade ago with games like Suikoden II (my favorite JRPG of all time), Star Ocean II, Xenogears, Chrono Cross, Final Fantasy IX and so on. But the last JRPG I played that I felt was really good is Suikoden V released in 2006 (which is a truly awesome game), and since then there hasn't really been anything that really grabbed me much. Lost Odyssey, The Last Remnant and Suikoden Tierkreis all been decent but not in a "OMG can't stop playing" kind of way as earlier JRPGs used to be for me, where one go to bed at 5am on the weekend.
But since then we seen WRPGs like Jade Empire (PC version, never played it on Xbox), The Witcher, Mass Effect, Dragon Age and Fallout 3 and they all been extremely immersive to me.
There are some aspects of JRPGs that I just find boring now, that I didn't mind much before. I feel the genre gotten stale and think the JRPG genre have 4 weak points that needs to be improved upon.
1) World Exploring. For some reason the FF series evolved to the worse here, FFX (and supposingly FFXIII which I have yet to play) offer no world exploring at all, but is instead just a very linear path. Go back and give the player exploration.
2) Random Encounters. Chrono Trigger was a fresh air back in 1995 when the random encounters stopped. Why do the genre in general still use them? I have absolutely no idea, but it's annoying, I want to see my enemies. Even Sands of Destruction, which was released this year, use random encounters.
3) Dialogue choices. Why let the player choose a Yes/No answer, when the game is http://tvtropes.org/pmwiki/pmwiki.php/Main/ButThouMust? It's a very poor illusion of player freedom and only hurt the game immersion. Offer proper choices, I was very surprised when I played Suikoden V and Steambot Chronicles, two JRPGs where dialogue choices actually mattered! More of that please. This especially matters when the main character acts like an idiot (like Vaan and lots of other JRPG protagonists) and the player have absolutely no chance of stopping it except moving the plot forward so the character "learn their lesson" and becomes mature. I hate that so much, I don't want to play an idiot, yet here we are forced to it. If there are no choices, at least let me play a smart person.
4) Less cutscenes. Japanese developers seem to love cutscenes, and while they certainly fill a function I don't want to watch a movie every 5 steps, I want to play a game. I stopped to play both Xenosaga and Metal Gear Solid 2 (which isn't a JRPG, but still) because of the annoying amount of cutscenes. Games should be interactive, movies have no interactivity at all. I like how the Suikoden series don't use that many cutscenes, but still tell really great stories and offer lots of interesting characters. Fortunately, http://en.wikipedia.org/wiki/Tetsuya_Takahashi (director of Xenosaga) have realised this and http://wii.ign.com/articles/106/1069861p1.html a while ago that he feels like cutscenes are a dead end and instead wants to make a game where the feeling of freedom is high. If his Xenoblade is ever released here in Europe I'm sure I will buy it, looks very good, even though it's for the Wii (which I don't have at the moment).
So yeah, I think that the JRPGs are in a decline, but I hope it will change.
As for the visual design of JRPGs with spikey hair and giant swords, meh, I couldn't care less, they have nothing to do with the story or the gameplay