With all of that in mind, allow me to inform your decision making if I can by offering some recommendations based on my own personal experience. I'm going to start by categorizing my recommendations into six categories that include clean boosts, tube screamers, distortions, transparent drives, fuzz pedals, and wacky outliers.
Clean boosts don't really offer too much gain or drive unless you really push the pedal to it's limits, or if the amplifier you're using doesn't have much head room. Clean boosts can be used to bump up your volume for certain parts so that they jump out a bit more, or they can be used in conjunction with other pedals if you're looking for added gain or tone control in your signal chain. Additionally, many clean boosts have their own distinctive tone and sound that can be very sought after.
The Xotic Effects EP Booster is an example of a clean boost pedal that offers its own tonal contribution to your sound. This effect is modelled after the pre amp section of a vintage echo plex, but with a much smaller footprint. Many guitarists that I know have gone through phases where this pedal was their "always on" boost pedal, but I have often used it as a boost for important parts or solos. This pedal compresses and fattens your tone in a very musical way, and while there is only one visible control knob, there are a few more switches on the inside for additional control.
The Spark Booster By TC Electronics is such an underrated pedal, and the perfect functional clean boost addition to any pedal board. The switch in the centre of the pedal that allows you to go from a "fat" to a "clean" to a "mid" tone makes this pedal a real swiss army knife for any guitarist. The "fat" option is wonderful for stratocaster players looking for a way to boost their bridge pickup without it sounding thin and shrill. The "clean" setting makes the pedal boost your volume without shaping the tone very noticeably at all which is perfect if you're looking to boost the tone of another drive pedal in your chain without losing the tonal qualities of that pedal, and the "mid" setting will allow your guitar to cut through any mix without the need for excessive volume increases. Additionally, depending on what kind of amp you're using this pedal can actually add quite a bit of drive to your sound, making it more than just a clean boost.
Tube Screamers contribute their own distinct tone to your signal, but they also push the front end of your amp (hence the name) and if you often play with your volume at a mid to high level on your amp, tube screamers can be the perfect way to achieve an over driven lead sound without sounding like a heavy metal guitarist.
The Ibanez TS 808 is really the gold standard of tube screamer pedals. If you're in the market for a tube screamer, you may notice that many different models are green in colour, or perhaps they have the same three knobs as the TS 808. This is because the TS 808 circuit has been imitated and even improved upon by many different pedal companies. If you're wondering how this pedal sounds, think Stevie Ray Vaughan. He famously ran two of these pedals in his signal chain. Since its release, the TS 808 has been discontinued, reissued, reproduced in hand wired versions, released as anniversary editions, and repackaged in just about every conceivable way. Vintage models or hand wired versions can be much more expensive, but for me the reissued version is one of the best gigging pedals I've ever used.
More so than clean drives or tube screamers, distortion pedals impose their own tone onto your signal and have less of a tendency to give the sound of your amp being "pushed". Distortion pedals can add gain or drive to your tone much easier and at lower volumes than tube screamers, and are often used for rhythm guitar parts that need to be overdriven.
The BOSS DS 1 has been a popular choice for guitarists for decades. Kirk Hammett has famously relied on this pedal to produce some of the well known overdriven sounds of Metallica's catalogue. While this distortion has been a staple for many guitarists, it has always remained on the more affordable end of the price range for comparable pedals, which makes it a smart buy for the money.
The Fulltone OCD distortion pedal has been one of my favourite distortion sounds for years. While it certainly imposes its tonal characteristics onto your signal (similar to the BOSS DS 1), it is also very touch sensitive, which is something that I personally love. This pedal really reacts to how aggressively you play, cleaning up for a lighter touch and driving harder with increased attack. The OCD pedal also dramatically responds to the volume control on your guitar. Should you turn the volume on your guitar down, the pedal will drive less. This type of responsiveness makes the OCD a very versatile choice for any guitarist looking to add a distortion to their pedal board.
Transparent overdrives seek to add no tonal colouring to your sound, rather to push your amp harder and bring forward the characteristics that your amp can attain when played at higher volumes, at the tap of a button.
The Emerson Transparent Overdrive is the most sought after transparent drive I've ever heard of. All of these pedals are hand wired and made by a small company in Oklahoma. There used to be a very long waitlist for these pedals, but these days they can be found online by a handful of retailers.
Fuzz pedals are over the top, very saturated gainy pedals. Think Jimi Hendrix or Jack White as a reference. Some of the earliest overdrive tones came from fuzz pedals and today there is no shortage of options on the market if you're looking for something conventional or even a little more modern.
The Big Muff by Electro-Harmonix is a classic choice for anybody looking at fuzz pedals. This pedal, similar to the TS 808 Tube Screamer mentioned earlier, has been tweaked and redone in countless iterations. If your needs for a fuzz pedal are specific, or you are already acquainted with the Big Muff, perhaps some of these more modern incarnations are for you. For the guitarist who is uninitiated in the world of fuzz pedals, the classic Big Muff model is a great place to start.
The ZVEX Fat Fuzz Factory is my favourite fuzz pedal. This pedal boasts some more nuanced tonal controls than many of the classic fuzz pedals for greater control and versatility. This pedal also includes a noise gate knob, which can be used to control the inevitable humming of a high gain fuzz circuit (especially for single coil guitars) but can also be used in more creative ways to produce gated glitchy lo-fi sounds.
These days there are certain overdrive sounds that really don't fit nicely into any of the previous categories, that still deserve to be mentioned in this article. There are countless models of overdrive pedals, and the ones mentioned in this article are really just some of my personal favourites, but there are so many more to be discovered and there are really no wrong answers about what sounds good. So, I will close this article by mentioning two pedals that have really piqued my interest this year.
The Plasma Pedal by Gamechanger Audio is one of the coolest "drive" pedals I've seen lately. I put the word "drive" in quotations because this pedal really doesn't sound like any conventional overdrive sound that I've ever heard before. I won't speculate as to how it works, but the weird lightning cylinder on the pedal moves in accordance with your playing. If you're interested in learning more about the pedal, check out this video here. What I find so impressive about this pedal is that no matter how unconventional it looks and sounds, it can also be used in very practical ways as a unique but functional overdrive tone.
The Blackstone Mosfet Overdrive is a pedal that has intrigued me for years. Hand wired by Jon Blackstone, this pedal has a reputation as being one of the most dynamic and responsive overdrive pedals out there. With two drive channels packed into a tiny footprint of a pedal, this hand built overdrive pedal has been on my mind for a very long time.
I hope that if you're in the market for an overdrive sound, some of my advice here helps to inform your decision making. As always, please don't hesitate to comment or to reach out with any concerns or questions! I am very humbled that you took the time to read my thoughts on this subject, and I'm proud to be a small part of your journey with the guitar.