So how can it be the worst interstate ever if it doesn't even exist?
Well, you have a good point. If you are only looking at existing interstates, I would vote for any of the suffixed routes: 35E and 35W, or now the NEW routes 69E, 69W, and 69C! One thought I have heard about 35E and 35W was to just make one of them I-33 and the other I-35 both at Dallas-Fort Worth and also for the Twin Cities.
Having lived in the Twin Cities, I never had a problem with I-35W/E. In that area, along with Dallas/Ft. Worth, the designation, though against AASHTO's wishes, makes perfect sense, and are very familiar with local residents. The original idea was to turn one of them into a 3di (likely 35E through St. Paul, part of which was in long-term freeway revolt limbo), but nobody in Minnesota could come up with a compromise. So they kept the suffixed highways. I assume the same thing occurred in DFW.
At least the two routes of I-35 reconnect at both ends of their suffixed run. The problem with suffixed interstates were spurred examples of roads like I-80 (most of them current I-76) that were just confusing and pointless.
Some people have a problem with the I-69 splits in Texas. While none of the routes connect with each other directly on the south end, the designations do make some sense, since all three routes go right to the border. I think giving each one its own distinct route number would be more confusing, but I-69E/C/W, as ridiculous as it may seem, does make some sense. I really don't think AASHTO's decisions and mandates are 100% perfect.