A great deal depends on how much money you're able to spend on a keyboard, as well as how you intend to use it. If you're looking for a keyboard that you can play on stage in gigs, then you should set your standards much higher than if you're just planning to learn with it and have some fun tinkering around at home, (I'm in the latter category myself.)
If you want something for performing on stage, then as far as Yamahas I'd recommend you consider nothing below one of the PSR-S models, or maybe a digital stage piano or synthesizer.
But for a beginner or for home recording, one of the PSR-E or YPT models might suffice if you don't need more than 61 keys, otherwise one of the DGX or YPG models with 76 or 88 keys would be good if you're more interested in playing compositions for the piano. The number of keys can be a matter of personal preference, with 76 keys being a nice compromise because they don't take up as much space as 88 keys yet provide a little more range than 61 keys. Still, 61 keys is usually adequate for playing organ or synth music.
Personally, I wouldn't get a keyboard with lighted keys for myself, because everything on a keyboard costs money, and if the manufacturer spent money to make the keys light up then they probably cut back a bit on other features to help keep the overall price down. In general, a keyboard with lighted keys won't have as many voices or other features as a keyboard without lighted keys. The EZ-220 does has a reasonable number of voices as far as Yamaha's entry-level models go, and it also has touch sensitivity (i.e., it's velocity-sensitive), but it doesn't have any chorus effects.
Yamaha's PSR-E and YPT models don't have lighted keys, but they do have the "Y.E.S." software ("Yamaha Education Suite") built in, and they have a small picture of the keyboard on their LCD screens-- the keys you're supposed to play will be highlighted on the LCD screen, although they aren't as easy to see as lighted keys would be.
There are also computer programs you can use with a keyboard that can show you which keys you're supposed to play next for a particular song-- Synthesia (which you mentioned) is one, but there are others-- so you don't need to buy a keyboard that has lighted keys or the built-in Y.E.S. software, because those things aren't necessary for Synthesia and similar programs to work.
For myself, I prefer the PSR-E400-level models (PSR-E443, PSR-E433, etc.) over the PSR-E300-level and PSR-E200-level models-- but if I could afford to spend a good bit more then I'd get the PSR-S670 because it's a much nicer keyboard than the PSR-E443. What I like about the PSR-E400-level models is that they have arpeggios, a pitch bend wheel, two assignable knobs for controlling sound parameters, and functions for changing the attack/release and cutoff/resonance of the voices, whereas the PSR-E300-level and PSR-E200-level models don't have those features. Even the older PSR-S models didn't have arpeggios or assignable knobs, although the new PSR-S models do.
If you can get a good price on a used PSR-9000, that could be a great keyboard-- but it's an older model that used floppy disks rather than USB thumb drives, so that might be a drawback, unless the previous owner had it modified to replace the disk drive with a USB port. Buying used can be tricky, because you need to be sure the keyboard is in good working condition, and you might even need to worry about compatibility issues if the keyboard is a really old model. It's always best to buy new if possible, but sometimes you can score a great price on a great used keyboard.
