BJJ would certainly be the most useful to learn if you're worried about 'real-world' fighting, however as Bronto described above at least half of their takedowns require you to 69 some other dude, so it's a hard pass from me. Taekwondo, while perhaps the least practical, always appealed to me the most. At the end of the day, you just got to do some research and find the one that speaks to you, practicality of each particular art shouldn't impact your decision tbh.