If you're just doing it for the fun of doing it then there's nothing wrong. If you actually are serious about becoming a Let's Player, you are not going to permeate the masses with such a popular game. The best way to start off as an LPer is to unearth a gem, dig up a great game that flew under the radar.
Of course, there's no need to do that off the bat. Even if you wish to become a full on LPer, you can still go ahead and do OoT or MM first and then move on to something that will separate you. Ideally you'll want to keep a healthy mix of fairly obscure games to draw the attention of people who hadn't heard of them, and more popular games simply to increase more traffic to your channel. After all, people won't be searching for videos about an obscure game.
That being said, no matter what game you do, you'll want to make sure you're fulfilling some conditions to create a good LP that a lot of people fall victim to:
- Sound quality. Don't even bother LPing if your sound quality is poor. You need to be clear, not muffled and audible. Many, MANY people fail as successful LPers for this reason alone.
- Voice. Make sure you keep yourself upbeat and cheerful, without getting annoying. Try and be funny but don't reach too far for jokes or do anything to obscene. Your main goal is to entertain the audience to hold their attention and make them like you. And that all comes in the voice and the way you present yourself. I suggest against doing videos late at night, when you are tired or when you are ill.
- Detail. Detail. Detail. This is what is often the dividing line between a mediocre LPer and a fantastic one. Cover sidequests, go 100%, post enemy bios, equipment requirements, anything you can think of that a player might want to know going in. For a better reference, check out Chuggaaconroy's LP of Pokemon Crystal. On every route he gives a list of all the Pokemon that can be found along with the time of day and the percentage of finding them. For a Zelda game, maybe just list how many bombs, arrows, rupees, etc you would need minimum to complete the area. That's just one idea.
- Tediousness. A lot of games have some section that is very long, difficult or boring. If during these sections you are not actually advancing in any way (think: level grinding in an RPG) then it's best to cut it out all together. If you do keep moving forward in the game but keep doing the same activity for a long period of time (think: the stealth section early in Windwaker) then it is probably best to speed up the video and add a music track over it, rather then keeping it at normal speed and running out of commentary.
- Live Commentary. Some LPers prefer to record a video and then add the commentary in after. While there are various reasons for doing so, in my experience it is best to just do the commentary live so the experience is more legitimate. For example, if something scared or surprised you, a live commentary would capture your reaction where a commentary done later would either require acting or just mentioning how scared you were. However, part of what makes an LP different from a walkthrough is that it's a more legitimate experience, you're supposed to get the feeling of watching someone right next to you play the game, with all of their emotional responses, good or bad.
- Spoilers. Even if a game is decades old and extremely popular, it is still not advised to discuss spoilers, as there may be people who missed the game and want to experience it through an LP.
- Audience participation. One great way to hold the audience's attention is to allow them to interact with you. Allow them to post challenges for you to attempt, such as the three heart challenge. Obviously you aren't obligated to do it, but if you can, and you feel like it, do so. It is a good idea to make your audience feel important.
- Don't Sing. Don't. At least, not for more than a few seconds at a time. Disregard if your voice is good, like really good. Even then, it's not a great idea.
- Voice acting. Some LPers will voice act the lines in the game. This can go either way depending on the quality of your voice work as well as the amount of dialog. It may be best to summarize unimportant dialog or to simply forgo voice acting all together. Another option is to just read the text aloud in your own voice and not try to act for the characters. This factor really varies depending on the specifics of the game.
Hope this helped in any way.