Using what Old Grouch posted in a comment at Chizumatic, I have compiled the following handy table:
| Ratio | Decimal | Use | Anime |
|---|---|---|---|
| 4:3 | 1.333:1 | NTSC | Ranma, To Heart, Manabi Straight (all media) |
| 17:12 | 1.417:1 | ? | Gundam 08th MS Team on fansubs |
| 3:2 | 1.500:1 | 35mm | |
| 16:10 | 1.600:1 | (no known anime) | |
| 5:3 | 1.667:1 | Euro wide | Mahoromatic on DVD |
| - | 1.741:1 | ? | Vandread (letterboxed into 4:3) |
| 16:9 | 1.778:1 | HDTV | Azumanga VSM, Figure 17, Clannad |
| - | 1.822:1 | ? | Porco Rosso DVD |
| - | 1.850:1 | Amer wide |
Unusual ratios are in bold. In both cases, it's unclear for me just what the master was. In case of 08th MS Team, the fansub master is often clearer than the poor parts of the DVD (which is also truncated to 4:3). Was it LD? But then, what TV standard? PAL? For Mahoromatic, I have to assume some professional tape, I guess.
All this is of mostly historical interest with the celluloid gone, but still.