While it was actually a little hard to find phrases in Katakana, as most of them were in Hiragana and Kanji, I did manage to find a few that I thought were interesting!
Some of the best of course refer to food and desserts!
ョコレート - Chocolate
ポテト - Potato
サンドイッチ - Sandwich
To name a few
Others are more random phrases.
グッジョブ - good job
ドンマイ - don’t mind, said usually used after someone else apologizes
And possibly my favorite, stolen straight from the show "Who Wants to Be a Millionaire?"
ファイナルアンサー final answer
Finally, these words from this powerpoint were too funny and interesting not to include.