Which is better Pokemon or Yu Gi Oh?
Yugioh has less cards per pack and less chance of good cards per pack. Pokemon is more social, yugioh is more thoughtful and competitive. Pokémon is certainly more popular, both in anime and outside sources like games and merchandise. Yu-Gi-Oh! is more relevant for its card game which attracts an older audience.
Is it worth collecting Yugioh cards?
Very few yugioh cards are worth collecting beside maybe prize cards and some turbo pack stuff. Most Ultimate and Ghost Rares will retain their value since they aren't printed in main sets anymore and they're the prettiest rarity of cards in the eyes of almost everyone.
Is Yugioh a ripoff of Pokemon?
Not in the slightest. Pokémon was originally a video game. That spawned a manga, card game, and anime. IIRC, Yugioh was originally a manga, then anime, and around the time of the anime the first proper cards(not the Bandai ones which were merely collecting not battling) were released.
Was Pokemon or Yu Gi Oh first?
Nope. Pokemon Greed and Blue came out in Japan earlier in the same year as the first chapter of the Yu-Gi-Oh! manga was released. The Pokemon anime came out about a year before the first Yu-Gi-Oh!