The Original Poster's Question
The film that I chose for the class to watch is called The Life of Igor.
The film which I chose for the class to watch is called The Life of Igor.
Both that and which can be used with restrictive relative clauses. A third possibility, is dropping the relative word altogether when the verb in the relative clause has its own Subject.
In the Original Poster's example, the relative clause has a subject, the word I. For this reason the OP could use the following version of the sentence:
- The film I chose for the class to watch is called The Life of Igor.
The Original Poster's core question, however, is whether there is any reason not to use which or that here. The answer is, no! There are no situations that I know of where it is wrong to use which for this type of relative clause. However there are several where it is wrong or silly to use that. The original examples don't fall into this bracket, but it is worth examining them anyhow.
When not to use that:
There are some special cases when we can't use that with restrictive relative clauses. The following sentences are fine:
- That's the man that you were talking with.
- That's the bullet that I was shot with.
However, if we move the preposition to the front of the relative clause, that cannot be the complement of the preposition. We have to use whom or which as appropriate:
[Notice that we cannot use who as the complement of a preposition. We have to use whom:
- *That's the man with who you were talking. (wrong)
Many writers on this site advise people not to use whom, but this is one situation where you have to!]
Another situation in which it's better not to use that, is after the demonstrative pronoun, 'pointy' that.
- ?Do not do that that you know to be wrong. (awkward)
This is not grammatically wrong, but it's a bit awkward, and it can be difficult to read. Lastly we may want to contrast the difference between a person or thing that might have done something. In this case we may want to say who or which. This cannot work with the word that:
- Never trust in any people or in any things who, or which, you cannot actually see.
- *Never trust in any people or in any things who, or that, you cannot actually see. (ungrammatical)
The Original Poster's examples don't fall into any of these three categories, so either which or that is fine here. However, this is a normal answer for sensible right minded readers. There are several other answers here, which argue that which is incorrect in restrictive relative clauses. To understand why this isn't the case, you may wish to read my answer "In defense of which" below.
In defence of which
The idea that which is not used for restrictive clauses is a myth promulgated in the worst English grammar text-books and style guides ever written. The greatest writers in the English language have continuously used which as a relative pronoun in restrictive relative clauses — as has everyone else too.
Some info from the post Sidney Goldberg on NYT grammar: zero for three, by Geoffrey Pullum, Professor of General Linguistics at the University of Edinburgh, coauthor of the Cambridge Grammar of the English Language (2002), shows how far through various books you would need to go before finding which appearing as a restrictive relative pronoun. The first number given in the list below shows the number of lines in the entire book. The second number shows on which line the author first used which as a relative pronoun in a restrictive relative clause:
- A Christmas Carol (Dickens): 1,921 lines, first occurrence on line 217 = 11% of the way through;
- Alice in Wonderland (Carroll): 1,618 lines, line 143 = 8%;
- Dracula (Stoker): 9,824 lines, line 8 = less than 1%;
- Lord Jim (Conrad): 8,045 lines, line 15 = 1%;
- Moby Dick (Melville): 10,263 lines, line 103 = 1%;
- Wuthering Heights (Bronte): 7,599 lines, line 56 = 0.736%...
Now, I know these authors are idiots who didn't know how to speak English properly, but just how did their editors and publishers get away with it? And all the people who decided to put these books on school syllabi? They, of course, should be shot.
Getting serious again: importantly, as Pullum also shows in the post A Rule Which Will Live in Infamy, there are situations when we, in fact, cannot use that for restrictive clauses and in which we have to use which. (Oh look one of them happened right there. I couldn't for example have written ... "and in that we have to use which"). Here are the three situations Geoff Pullum describes:
- The putative ban can’t apply when a preposition precedes the relative pronoun: The town in which she lived is grammatical but *the town in that she lived isn’t.
- The supposed rule should be ignored when modifying demonstrative that, because that which you prefer is clearly preferable to ?that that you prefer.
- The rule can’t apply to a conjoined which: We must trust the unknown entity who or which created us is grammatical but *We must trust the unknown entity who or that created us isn’t.
Here is the passage in which (Oh no, there I go again with another one!) the famous quote that Pullum is playing with appears:
“Yesterday, December 7, 1941—a date which will live in infamy—the United States of America was suddenly and deliberately attacked by naval and air forces of the Empire of Japan.” That was how President Franklin D. Roosevelt opened his famous infamy speech, 71 years ago. Ignoring the writing handbooks, he opened with a passive construction, which of course is just right for the rhetorical context (America as innocent victim). And he also ignored another bogeyman rule: He introduced a restrictive relative clause with which.
The answer to the OP's question, therefore, is that which can, and sometimes must, be used for restrictive relative clauses. It's not a mistake to do so.
I leave you with Geoff Pullum's last words from the link above:
Grammar snobs trying to show off their linguistic rectitude by playing gotcha with an invented rule that never matched educated usage; copy editors slaving away trying to enforce it; Microsoft Word blindly putting wavy green underlining under every relative which not preceded by a comma. What a senseless waste of time and energy.
Follow the Fowler rule if you want to; it’s up to you. But don’t tell me that it’s crucial or that the best writers respect it. It’s a time-wasting early-20th-century fetish, a bogeyman rule undeserving of the attention of intelligent grownups.