A couple people have recommended the Disgaea series, and I would like to reaffirm this.
I have more hours on the first Disgaea title than any other game, about 1200 hours.
Of course, I'm a sucker for RPGs, and tactical RPGs are my favorite, but this series is definitely high quality and has an easy to learn difficult to master aspect that makes it worth the $20 it must cost at this point. It has several end game functions to make it a worthwhile experience for a long time, and something like 12 endings scattered throughout the game. The music in this series is also amazing, I actually has the OST on my iPod for a couple months. Good stuff.
It's out on the PS2, PSP, and DS. Out of those three, the DS post actually has the most extra features.
Of course, no one is going to read this or consider buying the game, I felt like sharing anyway.
The downloader will download the installer when runned,then u gotta install the game using it.
Also a something which took me long to figure out, after you first log in the game once you run it, you get brought to the character select, after selecting a character, TYPE YOUR DESIRED NAME before confirming.
I won't help you with playing guides, you can find that yourself.