I readily admit that forsythia seems to irritate more people than it inspires. The big bright yellows erupt before most other shrubs have even had a chance to bud.
Used with a certain amount of discretion forsythia has a place in the 4 season garden. Tuck it into your shrub border somewhere out of the way. Use sparingly. After forsythia does it's thing the show is over. You won't notice it again until the following Spring.
There are a couple of things to keep in mind when using this plant. It is a very fast grower and can easily overwhelm a small space. It tends to sucker and can form colonies if left to it's own devices. A hard freeze while the plant is in bloom will often turn the bright yellow flowers to a soft brown mush.
There are several cultivars in production but most are indistinguishable from one another. 'Lynwood Gold' and 'Arnolds Dwarf' come to mind. Lynwood is the dominant cultivar of this plant. Arnolds Dwarf tends to max out at about 4ft in height, does not have a great flower and so has little to offer. Currently deer resistant.