Details, details, details! We need more info if you want suggestions that are germane to your situation.
What are you shooting - narrative, run&gun, interviews……?
Which specific camera?
How much sound-for-picture experience do you have?
Firstly, just buying a "better" microphone and plopping it on top of your camera will not get you better sound. Solid production sound is the result of knowledge, skill and dedication to capturing quality production sound.
The optimum position for the mic is above and slightly in front of the actor(s) aimed at the notch at the base of the actors throat. So, unless your actors do not move at all, the aim of the mic must be constantly adjusted to insure optimum pick-up.
Now, on to mics. Rode mics are relatively inexpensive when you consider the fact that professional mics for production sound can run up to and even over $2,000. They are usually connected to additional thousands of dollars of mixers and recorders. So immediately nix the bargain basement mics; they are poorly made, are overly hyped in some frequencies and, as they are Hi-Z mics, are prone to RF and EM interference.
Your project will only look as good as it sounds, because
"Sound is half of the experience"
If your film looks terrible but has great sound, people might just think it's your aesthetic.
If your film looks great and has bad sound, people will think you're an amateur.
Sound is the first indicator to the industry that you know what you're doing.
You should most definitely read "The Location Sound Bible" by Ric Viers; it's a good introduction into production sound.
Depending upon your camera one of the Rode mics will do a decent job as will the Audio-Technica ATR6550.
As always, I recommend that you retain someone to do the production sound for you, or renting what you need.