Those who read my book Sense and Goodness without God (or even some of my online work, e.g. From Taoist to Infidel, which I updated for my book) will know I was a devout Taoist for many years. It is the religion I am still most fond of, and would soonest return to if I discovered enough evidence refuting naturalism. Unless, that is, such evidence in turn confirmed or more strongly supported some religion other than Taoism. But Taoism has such an enormous explanatory power over against just about every other religion I know, I find it quite unlikely any other is true (if naturalism is false). I discuss this fact in an appendix on Supernaturalism added to my critique of Michael Rea's World without Design.
Because of my peculiar background in this regard, I often still get asked what the best translations of the Tao Te Ching are. Though one should not overlook the Taoist writings of Chuang Tzu, the Tao Te Ching is the most important Taoist scripture, of which there are dozens of translations of varying merits. I will only list here what I consider the "most useful" of those I was familiar with, for understanding both the original and potential message of Taoism as a worldview.
The first thing to say is that there is nothing definitive. No translation is sufficient to understand the text, as the Chinese is subtle and frequently brilliant, carrying a different range of connotations than English, and the Tao Te Ching plays repeatedly on the double and extended meanings of words, which can only be appreciated in the Chinese, unless you have read a wide array of English translations (and perhaps a commentary or two), which will start to convey to you the range of each word's meaning in its given context. Then you can build on what you understand on your own.
Of course, in Taoist tradition (and in my Taoist faith) it is really the Tao that teaches you, by directly merging and communicating with it (in a sense like the Western idea of the Holy Spirit). The text only points you toward the Tao, and thus you did not have to understand the text in every detail, only just enough to get a good foothold, to step off from in the right direction, and thus "find" the true Tao and commune with it (through meditation, reflection, and the atunement of your character and demeanor). Then would follow insight and understanding beyond what even the text can teach you. In reality, of course, all this is just an intuitive game of self-reflection, imagination, and contemplation, which I admit was very useful to me, but ultimately not really anything to do with the Tao of the Universe.
The single best place to start is the Robert Henricks edition, which relies on the oldest and most reliable scrolls (in fact representing something of a critical edition of extant manuscripts, which do not always agree). Henricks includes the Chinese along with the English, and adds a brief commentary to every verse or line, which is often useful. I have the original 1989 edition (now out of print), but the 1993 Modern Library edition seems to be essentially identical. Note that Henricks calls it the Te Tao Ching, believing that to be the original title (as it was always copied on two scrolls, one the Te and one the Tao, which Henricks argues became reversed in order over time), but that is not certain, and it doesn't really matter.
I would then compare this with the Ellen Chen, Stephen Mitchell, and Jane English translations to get an idea of the total range of meaning for any given line or word. The truth is somewhere in the middle of all these. The simplest and least contentious translation is the Jane English edition, though if you ever compare it with Henricks you will see it still has many defects. Similarly when comparing these with the other two. The Chen edition is perhaps overly literal, while the Mitchell edition overly interpretive. Still, the Chen edition, like Henricks, is more scholarly in its construction and utility. The Mitchel edition, in contrast, is often more what Mitchell wants the book to have said than what it actually does, though by stretching the possible meaning of the text his effort illuminates the potential range and limits of the original words in context. Combining a reading of all four translations will, I think, land you in the ballpark of what the Tao Te Ching originally, or at least potentially, meant to say.
These four represent the translations I settled on by around 1990 as the most useful, and thus the ones I know best. I produced my own "translation" by hand copying my preferred verses and lines from all four of these, into a hardbound diary, to take with me as my one devotional item in boot camp. There are many other translations (including several produced since I deconverted). My exclusion of others here does not necessarily mean they are worse (some may even be better), although I did look at every translation I could get my hands on by 1990 or so and thus any I do not include above probably did not rate well enough to be worth your interest (though that was so long ago I could not tell you now why).