I'd recommend checking out the following...for PS3. If you want Vita recommendations as well, just say and I'll give you another textwall, as there are substantially more titles I'd recommend for it, aha :3
For turn-based battles and a change of pace, you might want to try the Atelier series. There is less of an emphasis on battles in some games than others (I'd say Meruru, Escha & Logy and Shallie are the most battle-oriented titles) but they're pretty by-the-books in terms of battles and come with a delightfully easy to learn but difficult to master alchemy system. The time limit might be off-putting though, as well as the generally relaxed atmosphere. There are not RPGs about saving the world, they're mostly about people just trying to get by in the world. You get a truly fantastic cast as a result though.
Star Ocean: The Last Hope is worth trying out if you're interested in the Tales series; it's battle system is substantially better in that it allows easy full 360-degree movement and places a little more emphasis on tactics, since you can't use too many artes to just bully your way through the game. The cast offers a far wider variety of play styles too, and I'd say it's slightly longer than your average Tales game. Although if you're after trophies you need to avoid it like the plague, it's notoriously difficult (read: damn near impossible) to platinum it.
I'd recommend Resonance of Fate if you're looking for something different. It's...semi-turn based, shall we say? In that you can potentially avoid enemies getting a turn entirely if you're good enough. The problem is getting good enough: it's absolutely brutal. The gameplay is similar to Eternal Sonata, Neptunia Mk.II/Victory and Valkyrie Profile: Silmeria in that you move about on the battlefield for a set amount of time before selecting your attacks, although there is less of a focus on combo attacks and more on plotting your moves carefully. It has an unique steampunk setting and a nice sense of camaraderie between the three main characters, so it might appeal to you :3
If you weren't too keen on Disgaea I'd be hesitant to recommend The Guided Fate Paradox, but I have to give it a mention anyway, because it's a fantastically brutal rogue-like with a unique story and a fantastic soundtrack. It boasts Disgaea's insane level of grinding and stats, but has a slightly more serious plot (but only slightly; it's quite a bit like Disgaea 4 in this regard) and, whilst it's hard to get into, it's rewarding. I've heard the sequel, The Awakened Fate Ultimatum, is a lot easier, although I've not had a chance to play that yet. Busy busy.
Fairy Fencer F is another one you might want to consider if Neptunia looks appealing to you, it's made by the same team and has the same battle system, but is more of a traditional JRPG rather than a parody. It's quite a short game if you don't platinum it, and it's woefully easy, but it's quite a lot of fun nonetheless.
There are more. I'm forgetting something...but it's very early in the morning and I'm drawing from a sleep-deprived memory. xD
