Gunther
His appearances in the series:
116: The One With Two Parts (I)
219: The One Where Eddie won't go
221: The One With The Bullies
222: The One With the two Parties
308: The One With The Giant Poking Device
310: The One Where Rachel Quits
312: The One With All the Jealousy
313: The One Where Monica and Richard are Just Friends
316: The One The Morning After
318: The One With The Hypnosis Types
319: The One With The Tiny Tee-shirt
321: The One With The Chick And The Duck
322: The One With The Screamer
325: The One At The Beach
402: The One With The Cat
405: The One With Joey's New Girlfriend
408: The One With Chandler In A Box
410: The One With The Girl From Poughkeepsie
411: The One With Phoebe's Uterus
416: The One With The Fake Party
420: The One With All The Wedding Drawn up
422: The One With The Worst Best Man Ever
507: The One Where Ross Moves In
521: The One With The Ball
605. TOW Joey's Porsche
720. TOW Rachel's Big Kiss
Gunther is the secondary character who appears the greatest number of times in the series. He has a huge crush on Rachel and no one knows about it. Sometimes he is mistaken as being gay. He is a nice guy who works at Central Perk.