I'd strongly advise against buying another RTL dongle for HF. Good money after bad. I have two of them and they are OK for VHF/UHF work, I use one to listen to our county's trunked radio system on 900 MHz. Great value for $15. But for HF use? Forget about it. After you buy the converter, then spend money on a low pass filter to get rid of images, you still have a poor performing SDR, and are more than half way to a much much better SDR.
I have a few SDRs:
The KiwiSDR is probably the "easiest" SDR for most to get running. It's a self contained box with a CPU that acts as a web server. So no USB drivers to install, etc. You just plug it in, configure it, and use it on your computer via a web browser. You can use it from multiple computers at the same time, your tablet, and even share it on the internet. The only downside I have run into is that it can overload with strong signals.
The AirSpyHF+ is another good SDR, maximum bandwidth of 768 kHz. It's very sensitive, and a good performer. Also tunes part of the VHF band as a bonus in addition to HF.
There's a few SDRPlay models, I have a RSP1A. Good value for the price, and the wide bandwidth (8 MHz) is useful at times. Covers a huge range, LW/MW/HF/VHF/UHF up to 1700 MHz or so from memory. I am still getting used to the SDRUno software, which is very powerful with lots of features. As a minor downside, the AGC action can take a little getting used to.
I really like my AFE822x dual channel SDR. They make a single channel version AFEDRI as well. Great value for the money, and a solid performer. Buy direct from Alex in Israel, shipping is cheap, I think it was $24 to the USA. I use this on the 48 meter Europirate band, and it does a great job. I also use it portable with my laptop as it can be powered by USB, to sniff out RFI sources. It has an ethernet interface, so you do not need to install USB drivers. I love it. Not sure why the AFEDRI SDRs don't get much attention, they are really solid performers and excellent value for the money. I'd give up all my other SDRs (except the netSDR) before this one.
The netSDR is no longer made, but it's one of the Cadillacs of the SDR field. Solid performer. Built like a tank. No weird effects, it just works, and you can always believe what you see. Super sensitive. No images. It's my workhorse for the 43 meter pirate band, and the radio I turn to daily use on other bands when doing live listening. If you find one for sale used, buy it.