Guild Wars 2

Take a look at League of Legends for example. Every single ability (with maybe 3-5 exceptions for abilities that auto-smartcast because of their spammability) has a blue area that appears when you select the ability that shows you exactly your hitbox. Skillshots have well defined areas that also describe more or less what you should expect from the skill. Targeted abilities pop up a ring around your hero at the edge of the skill’s range and change the cursor to a targeting reticle. Autoattacks are excluded from rangefinding and the player is left to learn their hero’s auto range (mostly for graphical simplicity/elegance I think).

What do we have in Guild Wars 2?
Selecting a target puts a red bar under your skill if it’s out of range, or not if you’e in range. Deselecting targets does the same, but changes it to “if something is in range”.

What’s missing?
Players have no way to tell where the edge of their range is. We can’t know if we’re 1201 units away or 1300 because both ranges give us the same feedback on 1200 range skills (For a situation like this, it could be the difference between tapping your move key once instead of twice and saving your dodge while still getting in/out range quickly). We have to develop a sense of how far a given range is and are given no aids, making the game hard to pick up and hard to come back to.

What do I suggest you do about it?
Optimally, probably a system similar to League of Legends with a circle lighting up around you when you hover over or select a skill. Preferably with an off switch, and/or doesn’t activate on pushing a hotkey.
At the simplest, show us the number for our range to our target (for example, place the number under the target’s picture). It’s already calculated in real time for the red bars, just show it to us. Doesn’t have to be huge, just readable.