Just had a conversation on what lights should I buy with a photographer on twitter. I figured I would put up a quick post with a few thoughts on the matter. Like most things in photography gear the answer always depends. What you shoot, what budget you have, your priorities, how lazy you are, etc. Here are a couple of recommendations that are all over the map with a few factors for consideration.
If you have no idea what you might really want or need I would suggest not spending anything. Well how about next to nothing. I did the entire simulating sunlight eBook with one speedlight in manual mode restricted to 1/8 power. That was a conscious decision as I wanted people that haven't really looked at creative use of strobes to be able to reproduce anything in the book with virtually no investment. So for those just dipping their toe in. Find any old shoe mount flash, most people have one laying around somewhere. Nothing fancy. If you can control it's output that's good - even if you don't it's dirt cheap. Then get a way to fire it when it's not on top of your camera. Next up is a way to point it where you want it. A stand. I wouldn't bother with cables since off-brand radios like this are so freaking cheap now.
Moving on to the "lights" part. Personally I hate TTL flash. It's absolutely fine if you really only have ONE shot that you need to make very quickly and then move on to a completely different shot. If you are actually setting up a scene and moving lights around on stands I don't get TTL at all? To me it's a lot like hit or miss mode where your exposure can vary based on your framing. Screw it I much rather manual and have every shot of that scene exactly the same until I change it. If you need TTL great - just buy really expensive shit from your camera maker. It costs a bundle for what you actually get. Don't need TTL and you still want to be in the "I use tiny lights club" I would buy a gaggle of these. They have a built-in radio trigger so you don't need to buy one for every light. So cheap I wouldn't give a hoot about reliability or if they broke. Just make sure you have one more than you need on a shoot.
If I had a meager budget but wanted to buy lights and be completely done no matter what camera I used for the next 10 years I would buy Einsteins . Plenty of power. Color temperature consistency across power levels, remote triggering and remote power control as options. Done.
If budget is not an issue and you need everything then just buy everything from everyone and have every option under the sun at your disposal. Prolly not a great idea. Trying to buy lights for all occasions and all situations is also not a really great idea. I will say remote power control from the camera is extremely convienient. Especially if you need to work fast without assistants. Almost anything that does remote TTL also does remote power control. Honestly it's the only reason I have dedicated speedlights - just for the remote power control I use them on manual 99% of the time. The Einsteins have remote power control w/ out TTL - so do other big lights but they are at a great price point. TTL small shit costs about as much without the color consistency, power, or convenient lighting modifier selection. TTL wireless radio is idiotically expensive at the moment. Decide what you really really need and go with what you will use most of the time.
There really is no one size fits all.