Personally, after when I first played R-Type Final I was impressed. After playing it for a couple hours total, I got bored with it. Not because I was too good (far from it), but even on the harder difficulties it just seemed... boring. Not a whole ton of action, not a whole lot of stuff on the screen at once. That's just my impression of it. For $30, it's got replay value however.
Pulstar is a fun shooter. I'd get it as it seems to be more in tune with the previous "R-Type" games, meaning crazy action.