Most of the start of the Decalogue is pretty much the same, except for small differences in spelling, etc. One particularly notable difference is in the Fourth Commandment (by Jewish counting, see below), “Observe the Sabbath day to make it holy.” The Bible includes the Decalogue in two places: once here, and once in Deuteronomy chapter 5. In the Masoretic text, this commandment is worded slightly differently in the two places: here in Exodus, it says זכור את יום השבת “Remember the Sabbath day” but in Deuteronomy it says שמור את יום השבת “Observe the Sabbath day”, or “Keep…” The rabbis explain that the two terms stand for the two aspects of the laws of Sabbath: “Remember” refers to the positive commandments, and “Observe” refers to the negative commandments, and the two words were miraculously pronounced by God (and just as miraculously heard and and understood by the Israelites) simultaneously.
The Samaritan text, as usual, is more consistent: שמור “Observe” in both places. This is the less well-known of the two versions to most non-Samaritans, I think, which makes it a little more noticeable.
We already know that Jews and Christians count the Commandments a little differently from each other. Jews consider “I am YHWH your God…” to be the first commandment, and “You shall have no other gods before me” is the second (note that the term used for the Decalogue in Hebrew isn't the Ten Commandments, but עשרת הדברות, which is more like “the ten utterances,” which explains how “I am YHWH your God…” can be a Commandment—it doesn't have to be, it's an utterance). Then the commandment-numbers are off-by-one wrt the Christian count (which considers “I am…” to be just introductory, or else part of the first commandment along with “You shall have no…”, until the end, where Jews consider “You shall not covet your neighbor's house” and “You shall not covet your neighbor's wife…” to be the same commandment. Hey, it's all just “Don't covet, mmkay?” Christians count coveting wives to be a distinct commandment from coveting houses.
Samaritans begin the count like Christians but end it like Jews, because they have more text to include. Their version of the “coveting” commandment also includes the word “his field,” thus including that in the list of things not to be covetted, and it has the conjunctions structured a little differently, so as to group slave and maidservant together, and ox and donkey.
The Samaritans have one more commandment. Recall that probably the central disagreement that caused the schism between Jews and Samaritans was where to put the Temple, i.e., where this place that God “set his Name” was, that is referred to many times in the Torah. Jews say it is Mt Moriah in Jerusalem, and Samaritans say it is Mt Gerizim near Shechem (Nablus). Both texts specify Mt Gerizim as the mountain of blessing for a ceremony to be performed by the Israelites upon crossing the Jordan (See Deuteronomy chapters 11 and 27), so even according to Jews the Samaritan position is not completely without support.
The Masoretic text frequently refers to “the place where YHWH will choose to set his Name,” the place where sacrifices are brought, etc. In the Samaritan text, all these references are in past tense: “the place where YHWH has chosen to set his name.” In their version of the Torah, right here in no less distinguished a spot than the Ten Commandments, Just after the commandment against covetting, the Samaritan text spells out, in words similar to those used elsewhere, the commandment to set up an altar and a monument of plastered stones with the law written on it on Mt Gerizim and bring sacrifices there (See Deuteronomy chapter 27; in the Masoretic text the location is given as Mt Ebal). I suppose it isn't actually any more explicit about designating it as the place than the Masoretic text is in Deuteronomy, but certainly the placement here does add importance.
In Moses' retelling of the events surrounding the giving of the Ten Commandments, in Deuteronomy chapter 5, he gives details about the Israelites' reactions and God's reactions to them which are not in the text here… but they are in the Samaritan text. It looks like it isn't a simple restatement of what's in one place either; it seems that what is stated here is stated again elsewhere in smaller pieces.
OK, I stalled on finishing this up for weeks; I better get this published without messing with it any more.