Depends on your situation in what you want to spend. For me, I love the Ego S2 slider net. Unlike a normal extension net that extends one way (doubling the length), the Ego extends from the middle. The front slides forward while the back slides back. Smaller package to get the same results. They have one that is 48" that extends to 108"!
We land everything from walleye to salmon and steelhead in ours. Plenty sturdy. They are rubber and you can get them in several configurations from deep to shallow.
EGO S2 Slider Products - Landing Nets
I have OCD "Obsessive Crappie Disorder"