Screw Bonds , Canseco, Sosa, Mcgwire and the steroids bullshit as being worst. Baseball has always been about cheating, about getting away with what you can. If you're not cheating, you're not trying. Steroids just took it to the nth degree.
I voter other because expansion was the worst. Washington(Expos should have been contracted), Tampa, Florida, Colorado and Arizona. Expansion watered down everyone. Expansion brought hitters parks to baseball(except Fla. still has no stadium). Expansion hitters parks bought "bandbox" parks all across the majors. Hitters parks and expansion brought shitty pitching all over the Major Leagues. Shitty pitching brought high salaries for the few pitchers that were very good. Those brought salaries up for other pitchers and big hitters. Eventually all the salaries came way up. As salaries went way up, the number of teams that could pay them went down. It seems every 5 or so years we have a few different teams that join the 'spending crowd' and somethat drop out. The Yankees have always spent alot. The Red Sox joined the insane salary club when the current ownership took over. During the '90's the Braves and Indians were big spenders. The Angels, White Sox and Mets have been added, although the Mets have always been a big spender.
It's gotten to the point that the teams that can't afford to pay the big salaries are forced to trade their good, young players during the last year of a contract because they can't afford to pay the players what one of the biggies will pony up.
Some teams play it smart and some just don't care because they're getting paid from the higher payroll clubs. If you're a historically shitty team, you should have the best farm system, yet the Pirates, Royals and Brewers still suck.
The bottom line is a pitcher with a 4.20 era last season parlayed that into a contract worth 16 Million next season. Two players that have never played in the Major Leagues were paid over 60 Million with another 78 Million paid for the right to negotiate with them.
The best thing about baseball is that it kills time until football season.