すばらしい
wonderful; splendid
素晴らしいスピーチでした。
It was a wonderful speech.
Practice using this in both attributive (before noun) and predicative (end of sentence) positions. Try to learn this with its opposite adjective for stronger memorization. At N3 level, knowing this word helps bridge basic and intermediate Japanese.
From the JLP Quiz question bank — the word in the form it is actually tested in.
こんな素晴らしい景色を見たら、写真を撮ら___。
Answer: ずにはいられない
今回の試験は難しかった。全員が合格した___は本当に素晴らしい。
Answer: ということ