"It is our choices...that show what we truly are, far more than our abilities."
-J. K. RowlingHarry Potter and The Chamber of Secrets


Addition In addition, in addition to, additionally, another, besides, moreover, further, furthermore, equally important, much more interesting, of even greater appeal, more specifically, accordingly, in fact, likewise, next, too, then, and, both … and, not only but (also), first, second, in the third place (do not use firstly, secondly, thirdly. and soon)
Comparison similarly, likewise, in like manner, by comparison, compared to, vis-à-vis, just as surely, in the same way, not only … but (also), both … and, either … or
Contrast but, however, yet, still, nevertheless, on the one hand on the other hand, for all of, on the contrary, notwithstanding, in contrast, in contrast to, rather, neither… nor, although, though, in spite of, whereas
Emphasis in fact, indeed, indeed, in truth, in any event, certainly, definitely, emphatically, unquestionably, undoubtedly, without a doubt, undeniably, without reservation, naturally, obviously, not only… but (also), both … and
Example for example, for instance, in this case, in another case, on this occasion, in this situation, as proof, as evidence, take the case of …, proof of this, evidence of this, thus
Exception yet, still, however, nevertheless, in spite of, despite, once in a while, sometimes, nonetheless, though, although
Place near, beyond, opposite to, adjacent to, at the same place, here, there, from, over, in the middle, around, in front of, in the distance, farther, here and there, above, below:, at the right, between, in the foreground, on this side, beside
Purpose to this end, with this object, for this purpose, in order that, in this way, since, so that, on that account, in case, with a view to, for the same reason
Repetition in other words, that is to say, as I have said, again, once again
Result accordingly, thus, consequently, hence, therefore, thereupon, inevitably, under these conditions, as a result, is a consequence, because, because of, so that, not only… but (also), so … as
Sequence first, second, third, A, B, C, 1, 2, 3, next, then, at the outset, following this, at this time, now, at this point, after, afterward, after this, subsequently, lastly, finally, consequently, before this, previously, preceding this, simultaneously, concurrently
Summary in brief, on the whole, in sum, to sum up, to conclude, hence, for this reason, in short, in summary, in conclusion
Time at once, immediately, at length, in the meantime, meanwhile, at the same time, in the end, in the interim, then, soon, not long after, at length, at last, finally, some time ago, later, afterwards, presently, from this time on, from time to time, after, before, until, at present, all of a sudden, instantly, at this instant, suddenly, now:, without delay, in the first place, forthwith, quickly, at this point, a few: minutes later, formerly, yesterday, later in the day, since then, when, whenever, next, as, once, since, occasionally, henceforth, meanwhile, thereupon, sometimes, in a moment, shortly, whereupon, previously

Source: John F. Parker. The Process of Writing. United States: Addison-Wesley Publishers Limited, 1983.