Done hate me for saying so, but it depends…
That’s all too true, but let me see if I can give you a little guidance. I’ll start by offering a few parameters so we know the rules of the game. In this case, I’m going to recommend based on this being an angler’s first and only fly rod…for now anyhow. 😉
To give the most generic answer possible, most industry folks would say a 9ft 5wt. While it may not be the perfect tool for every fly fishing scenario, it’s heavy enough for some light streamer work and bigger fish, and light enough to still have fun with smaller ones. And when it comes to Central Texas fly fishing or targeting warm water species with bigger poppers & streamers, lots of fishy folks will tell you to get a 9ft 6wt. That advice, while sound, is a little over-simplified. So if you’re like me, like to understand the why and gain a little more perspective, then read on…
An 8-9 ft 4-6wt rod is a good choice for a first rod depending on the waters you plan to fish.
If in doubt, get a 9ft 5wt.