He should play ALttP, OoT or SS since they are good starting points. ALttP is perfect in my opinion. Perfect dungeons, perfect enemies, perfect items, perfect music, perfect everything. The game also introduced the Light and Dark World system which does appear in other forms in other games(Past and Future from OoT,ect). ALttP pretty much improved on what Zelda 1 and Zelda 2 did. Of course the gameplay style is like Zelda 1 since it has that bird eye view and you can use items. Some of the elements that were take from Zelda 2 were NPC's(the people gave you an easier time in ALttP), a magic bar, ect. Overall, ALttP is a masterpiece and its a good way start the Zelda series or at least a good way to start on the 2-D Zelda games. I would give it 5 Maidens trapped in Crystals out of 5.
Now onto OoT. Even though OoT is extremely overrated, it is overrated for a good reason. It was the first 3-D Zelda game, and OoT was probably the first Zelda game that people have played. It is a very good transition from 2-D to 3-D because it felt like a Zelda game but at the same time it was a brand new experience. Good dungeons, perfect items, memorable characters, memorable soundtrack and overall, OoT is a classic. If you want the complete Zelda experience, then play Ocarina of Time. 5 Ocarinas out of 5.
Now onto the latest Zelda game, SS. Now SS, is my favorite game. The controls are amazing, the story and characters are excellent, every item is useful, amazing dungeon design, a lot of awesome collectables and upgrades and many more. I do think the game does share some flaws however. For one, I do think the puzzles are kinda easy but I've been playing Zelda for a long time so it doesn't really matter. Now, the story is pretty linear and if you played TP or WW then I think you can understand what I'm talking about. There are also some missed opportunities but I'll talk about that some other time. Other than the flaws, the game is very good. Like I said, SS is my favorite Zelda game. The positives outweigh the negatives and if Nintendo fixes the flaws of SS, then the next Zelda game will be perfect. Forget the rating, just buy the game!
I would start with any of these games, but every Zelda game is good but people should play the Zelda game that will make them a fan.