Taylor Swift has a vast collection of music that spans various genres and styles, making her songs suitable for a wide range of preferences. Here are some popular Taylor Swift songs that could be great choices for ringtones or caller tunes on phones:

"Shake It Off" - A catchy and upbeat pop song with an infectious chorus.
"Blank Space" - Known for its memorable lyrics and catchy melody.
"Love Story" - A classic Taylor Swift song with a romantic theme.
"You Belong with Me" - A pop-country crossover hit with a catchy chorus.
"I Knew You Were Trouble" - Features a blend of pop and electronic elements, with a memorable hook.
"Delicate" - A dreamy and atmospheric pop song with heartfelt lyrics.
"Style" - Known for its sleek production and catchy melody.
"Wildest Dreams" - Features lush production and a captivating melody.
"Lover" - A romantic ballad with heartfelt lyrics and a nostalgic feel.
"ME!" - An upbeat and colorful pop anthem featuring Brendon Urie.
These are just a few suggestions, and Taylor Swift has many more songs that could make great ringtones depending on personal preferences and favorite tracks.