I use a Tech 21 Blonde from the (discontinued) Sansamp Character series. It is the pedal that the Joyo American Sound pedal is supposedly a copy of. I am very happy with the sounds I get out of it. It is an analog pedal and it acts very amp-like, with or without overdrive pedals in front of it. It is buffered (even when it's off) so it can serve a couple of purposes on a board. I like it a lot. I use it going into a clean amp, PA, or a mixer for recording.
I tried a Mooer 006 Micro Preamp, which was attractive to me because of its size, but I did not like it nearly as much as the Tech 21. It is digital, not analog, with two channels (clean/dirty), but it was harder to dial in sounds I liked. I found the tiny control knobs to be kind of a pain, and because the settings can be set independently for each or the two channels it is difficult to know what they are actually set at (not necessarily the same as where they are pointed). It is also true bypass, plus I did not think it reacted well to OD pedals in front. The flashing light when speaker emulation was set to "on" was distracting. Current draw is 300 mA, which is kind of high but probably not an issue unless you're trying to run a board from a battery. (Fortunately, it also sells quickly on Reverb.)