Sony FE 20-70mm f4G is the best choice.

For travel, I actually prefer a two-lens setup: the Sony 20mm f/1.8 G and the Sony 200-600mm G. The 20mm is incredible for landscapes, architecture, and night photography (that f/1.8 aperture is a lifesaver in dimly lit interiors). The 200-600mm handles everything else. Yes, there's a gap in the middle, but I find I rarely shoot in that range anyway. The image quality from both lenses is stellar.

Honestly, I’ve gotta agree that the 24-105mm is a fantastic middle ground, but after shooting with that focal range for 3 years on the a7 III, I think it’s worth looking at the f/2.8 options if ur planning on doing indoor architecture or late-night street photography in Europe. Here is how I’d break it down based on my long-term experience with these systems: 1. Sony FE 24-105mm f/4 G OSS: The OSS (Optical SteadyShot) is a lifesaver because the a7 III's IBIS is a bit dated compared to newer bodies. The 105mm reach is perfect for picking out details on old buildings. But, f/4 can feel really limiting once the sun goes down or you’re inside a dark cathedral. 2. Sigma 24-70mm f/2.8 DG DN Art: This is basically a GM-lite. The sharpness is incredible and the build quality feels pro. It handles chromatic aberration much better than the kit lens, but it’s definitely the heaviest of the bunch. 3. Tamron 28-75mm f/2.8 Di III VXD G2: This is my current travel go-to. It’s significantly lighter than the Sigma, and the G2 has way better AF tracking thanks to the VXD motor. Basically, if u don't mind the weight, get the Sigma. If you want to stay light, the Tamron is the move.

Yeah, I totally agree with the point about needing something that can handle those dark interiors. I've been diving into a bunch of performance tests lately because I'm still trying to learn what makes a lens actually 'good' for travel, and it's crazy how much the benchmarks matter when you're actually out there. - Honestly, just go with Sigma. Their stuff is built like a tank and the real-world performance is usually top-tier for the price.
- Focus on how the autofocus holds up when things get busy or crowded in the city.
- Look for something from those third-party brands that prioritizes contrast over just raw sharpness. But yeah, basically any of the newer glass from the big third-party names will probably blow that kit lens away. Idk though, do you guys find that the weight of the heavier high-performance glass actually messes with the balance of the a7 III? I’m still a bit worried about my wrist getting tired after a full day of walking!

I've been traveling with the Tamron 28-200mm on my a7 III for two years now and it's been a game-changer. For European cities where you'll be walking all day, having that single lens versatility is priceless. The image quality surprised me - it's not quite GM level but definitely punches above its weight. The light weight and weather sealing have proven invaluable during unexpected downpours in Paris and long hikes in Cinque Terre. At half your budget, it's also excellent value, leaving room for other travel essentials.

Saving this whole thread. So much good info here you guys are awesome.

For ultimate versatility and great image quality on your a7 III, the Tamron 28-200mm is a strong contender within your budget. If image quality is paramount, the Sony 24-70mm f/2.8 GM II is exceptional, though pricier. A solid mid-range option is the 24-105mm f/4.