The quality of tomatoes often depends on the weather, especially if they're grown outdoors. Possibly yours, because they were grown in pots rather than direct in the soil suffered intermittent water problems (too much or too little) which has toughened the skins as they try to continually adapt to the conditions in which they're growing. . I'm surprised you found your Gardeners Delight tasteless - they are generally reckoned to be one of the varieties with the best flavour and I never have a problem with mine.
Cherry tomatoes often have more flavour than the larger varieties. You could try growing Red tumbler or Yellow Tumbler which are low bushy varieties rather than tall ones, which produce cherry size tomatoes. They grow no more than 12 inches high so don't have to be tied up to a stake, and they don't have to be sideshooted either as the sideshoots grow flowers too and produce more tomatoes. These are both quite prolific varieties.
If you want to grow upright tomatoes, try Sungold which is a poular yellow cherry tomato or Idil which is a grape shaped yellow tomato which has hundreds of tomatoes on each truss.
if blight is a problem in your area, grow Ferline. It's an F1 variety which is blight resitant. The fruits are on the bigger size of medium, and it's a good cropper.