1) Blue Jays - obviously, but I was born in the States and moved to Canada at age 11, so I only transitioned into Jays' fandom. Although I first started watching them a lot some time around 1989 or 1990, and certainly loved the World Series years, it was really my years in Toronto as a grad student (early--to-mid aughts) that I fell in love with the team, despite their mediocre performances.
2) Mets - before I moved to Canada, I lived in Colorado, which at that time had no Major League team. I started following baseball in 1987, and loved Darryl Strawberry and Dwight Gooden. I still have a soft spot for the team (the first Major League games I watched were at Shea Stadium), and I love NYC.
3) Pirates - family connections to Pittsburgh, which is another great city, and I saw a few games there back when they had both Bonds and Bonilla.
4) Twins - again, I first started following baseball in 1987. I loved watching Puckett in the playoffs. They have long been my second-favorite AL team.
5) Nationals - If only for the Expos connection, although Washington DC is another city I really like a lot.
6) Rockies - despite not existing when I lived in Colorado, Colorado was my first home. I was born in Denver.
7) Mariners - I have seen the Jays and Mariners play in Seattle - so much fun, and a great stadium! Seattle is now the closest MLB team to me, too. Interestingly, the first Jays game I saw at Skydome was against the Mariners, with Griffey patrolling CF.
8) Tigers - went to see them during their 119 loss season, and had a lot of fun.
9) Dodgers - bonus points for being my Dad's favorite team when he was little (albeit the Brooklyn incarnation) and for breaking the colour barrier.
10) Phillies - of course, not pleased with their clash with the Jays, but Halladay was my favorite player for a long time.
11) Red Sox - this is tough. I hate the Red Sox as a team, but I'd still rather watch them than a lot of the meh teams, and I don't have the same visceral reaction to them as I do to the Yankees. More importantly, though, my all time favorite live baseball experience was at Fenway Park: such an amazing atmosphere.
12) Giants - most of the next few teams feel pretty "meh" about, but San Francisco - two thumbs up!
13) White Sox - my brother lives in Chicago's South Side. I've never been a huge fan, but I like the kinda working class connotations of the south-siders, and Chicago is one of my favorite cities.
14) Brewers - never been, but I'd like to visit
15) Astros - relatives in Houston!
16) Cardinals - yes, a great baseball organization, but I've never felt all that strongly about them, either way
17) Reds - see Cardinals, above.
18) Angels - relatives in LA! Trout is awesome! What's with the rest of the team?!?
19) Athletics - points for starting the sabermetric revolution and for agreeing to trade Donaldson! Lose a lot for the horrible stadium
20) Diamondbacks - ummm
21) Rays - I liked them better before they were good, but now that they're bad again, they may start moving up these rankings
22) Royals - I liked them better before they were good, now they just annoy me.
23) Cubs - love the city, but never really liked the fans.
24) Orioles - Don't like the team at all, but I like the stadium and the city, and thought Cal Ripken was amazing for many years
25) Marlins - can't like them because of Loria.
26) Padres - would feel more middling about them, except for their awful camouflage uniforms. Ugh.
27) Yankees - would have scored higher if they still had their old stadium. Now they just seem boring and corporate, plus I can't stand them as a Jays' rival.
28) Rangers - they make me the angriest of all the teams here. I hope Bautista hits 15 home runs just against them this year.
29) Clevelands - I actually kinda like the Clevelands as a team right now, but ugh, that horrible, racist logo. I just can't.
30) Braves - tomahawk chop. Upside down Canadian flag. 'nuf said.