This is what I'm rockin' in my 2005 4th Gen Sport: I went all out building this for performance and an incredible sound stage that'll have your ears ringing.
--> Alpine-iLX-W650 receiver and KTA-450 amplifier (50 watts RMS x 4 at 2 or 4 ohms) ~$584.89 pkg.
Alpine iLX-W650 and 4-channel Amp Package Includes iLX-W650 multimedia receiver, dockable KTA-450 amplifier, and amp wiring kit at Crutchfield
For my 2011 5th Gen SR5 I went 'budget' instead of performance: A really nice head unit for the money.
--> Boss BV800ACP receiver ~$249.99
Boss BV800ACP Digital multimedia receiver (does not play CDs) at Crutchfield
Both of these are double-din, touchscreen w/ CarPlay for both iPhone and Android.
Issues w/ the Alpine: CarPlay USB cable connects to the back of the unit "inverted" which is a pain in the !@#$. I anchored it w/ a zip tie to the antenna input connection to keep it from moving. Even still, the USB cable can be flakey as hell and the unit will show "Device Unsupported" if the connection is weak. To remedy this use a good solidly made Lightning cable. I recommend getting an Anker cable:
https://www.amazon.com/stores/page/9...-50C640189C14/
Also: Alpine does not support their flagship top selling HU, the iLX-W650 on their Tuneit app. ??? Come to think of it... not much support, period!
Issues w/ the BOSS: If you are connected to CarPlay and have an iPhone 12 Pro Max you can consistently expect to hear voice echo. There are a few ways to remedy or work-around since Apple won't own up to it being the phone at fault. Again, I recommend an Anker cable. Regardless of what the manual says, install the mic on the steering wheel column right behind the steering wheel for optimum call quality. Also turn down the CarPlay gain a few notches from its default setting or until you find the sweet spot.
Also: When connected to CarPlay your B-Tooth is disconnected. When using B-Tooth for calling instead of CarPlay you will NOT have a voice echo.
BOSS also has a built-in internal amp (20 watts RMS/80 peak x 4 channels)
I agree with an earlier Reply in that Kenwood is always a good choice as it was my goto back in the 80's and 90's.
Note: If you order from Crutchfield they will give you vehicle specific accessory options i.e. metra harness, and installation gear, steering wheel module, etc. And usually throw some of it in for free. You also receive personalized installation instructions to go along with you order. Lifetime technical support and superb customer service and "no hassle" return policy.
Units w/ touchscreens 9" and above be prepared to pay more than what I paid for both. The cheapest one I found was $349 and they go well over $1,000+ depending on the model.
I am very happy with both of the head units in my 4runners.
Hope this helps, and good luck!