"Good" is relative
And also depends on the kind of money you want to spend.
I'm very happy with the way my '67 rides and handles. It's a little stiffer than most, due largely to 540lb coils in the front and 4.5 leaf springs out back. But it handles quite well. Not well enough to keep up with a bunch of imports on windy country roads (as I found out during a spirited "cruise"), but quite a bit better than most people expect from a car fast approaching 50yrs old.
My typical recommendations are as follows:
1) Shelby UCA relocation. Relocating the UCA mounting points changes the camber curve, providing negative camber at the outside tire, resulting in more tire contact (more traction) and a lower roll center (less body roll in corners). The end result is a front end that feels like you just added a monster sway bar, but without any of the added ride harshness. There are no downsides to this mod, and it's free, aside from some drill bits and a template. Just make sure you get the template for 65-66, as the 67-70 template is different.
2) Roller coil spring perches. They make a huge
difference in suspension response. The factory spring perch bushing is very stiff and doesn't allow for proper articulation, causing a bind and preventing the shock and coil spring from acting smoothly as separate entities. This bind can also result in a broken shock under extreme conditions. I broke a brand new Edelbrock shock like this before switching to roller perches. By allowing the perch to rotate freely, you allow the shock to operate properly without any side load, resulting in a smoother, more responsive suspension.
3) New coil springs. You'd be surprised how much a new set of springs can change the way the car feels. If you want a smoother ride, stick with GT springs. If you want something sportier, go with a set of 540lb springs (most places advertise these as "620" springs, which usually refers to the coil diameter, not the spring rate). I have a set of Grab a Trak 540lb springs and I'm pretty happy with them, although I plan to hack off about 1/2 a coil to even the front out with the lowered rear.
4) Proper size sway bar for the front. 7/8" is good for a nice firm, sporty feel. This is what I run. A 5/8" will give you a better ride, but allow a bit more body roll.
5) Shocks, as mentioned. The better the shock, the happier you'll be. Monroe doesn't make anything decent for these cars, so don't even try that route. KYB GR-2's will ride fairly smooth, but won't help handling much. A set of custom valved Bilsteins from Maier Racing will compliment the upgraded springs, but won't rattle your teeth out like KYB Gas-A-Justs.
6) New suspension parts. Old, worn out bushings and ball joints will handicap your suspension. Stick with quality parts. Moog is pretty much top of the line, although Mevotech makes good stuff as well. Spicer/Raybestos is ok (they use nylon ball joint sleeves, which wear out quicker), but that's about as cheap as I'd recommend. If you really want some slick UCA's, get them from OpenTracker Racing. He sells a set of UCA's with deburred shafts and tack welded end caps that I'd like to get my hands on.
6) Good steering parts. A sloppy steering system is going to make turning sloppy. Many shops will do a free suspension/steering check for you. If something has play in it, replace it.