led I can stick on a AA battery
All non-infrared LEDs I can think of have a forward Voltage (i.e. the voltage across the diode when driven at the recommended operating current for full brightness) significantly enough larger than the 1.5 V you could get out of an alkaline battery.

So, since your voltage is already below what your LED can tolerate at most, you don't actually need a series resistor to drop the voltage difference between supply voltage (1.5 V) and max-current forward voltage (e.g. 1.7V for most red LEDs).

You, however, also don't get full brightness from this.

Problem is that  diodes have exponential current/voltage curves, so you go down slightly below the forward voltage, your forward current drastically drops, and thus, the amount of light emitted.

Thus, best case, you need a really low forward current LED. Red is probably your only choice.

But even with a long-wavelength red LED (which can have a nominal forward voltage of 1.6V), 1.5 V (ie. a room-temperature brand new AA battery) is at the very lowest end of visibility.

So: nope, there's no LED that you can directly stick onto a single AA battery.


  and do they still come with thin stiff wire long metal legs that can be bent, hold a shape and remain put?


The wired form is typically sold as "for through-hole mounting", and yes, it's still widely available.

Don't really understand where you're going with the "really long wire"; you're soldering, anyway,so soldering wires of exactly the length you need should work.


  and also, they are still a diode, are they forgiving of the polarity or will they blow if placed the wrong way round?


The reverse breakdown voltages of LEDs are typically > 4V, so you won't crack that with a single AA battery and are on the safe side.