If I want to list two or more activities I like to do in one sentence, do the verbs preceding the last one that comes before のが have to be in て form, as in this sentence:
旅行をして、映画を見るのが好きです。
I like to travel and watch movies.
Or should the verbs be in dictionary form?
I am not sure whether the sentence above should be similar to listing two or more actions in a sequence, as in this sentence:
旅行をして、映画を見ました。
I traveled and then watched a movie.
If you are listing multiple actions in a set (eg. of things you like) then you would use verb+たり〜verb+たりするのが好き.
旅行したり、映画を見たりするのが好きです。
I like to do things like watching movies and travelling.
Your initial sentence reads like the two actions are connected. As you like to first travel somewhere and then watch a movie there.
I agree that James Scott Tayler's answer is correct, however strictly speaking the verbs could also be in the dictionary form. For example:
旅行するの（が）好きだし、映画を見るのも好きです.
I like traveling, and I also like watching movies
