C: linked lists or dynamic arrays?

As a general rule, should C programs use linked lists or dynamic arrays?

Linked lists if you need O(1) insertion at the beginning and tail(). If you don't care too much about space, you can use a doubly linked list (or, just use the xor trick).
Dynamic arrays if you need O(1) insertion at the end and random access.

The dynamic array has faster indexing - array to list, O(1) versus O(n) - but the linked list performs faster insertions at the front - array to list, O(n) versus O(1) - and insertions in the middle - array to list, search time + O(1) versus O(n).  Some of these speed concerns can be mitigated by using a variant of a standard dynamic array.

As a general rule, your program should use whatever is the best implementation for your intentions.