It very much depends on your light levels and whether they are all going in pots?
However, dahlias tubers are pretty cheap and give flowers in the first season. I never lift mine but do make sure that the ones in the ground get a good mulch at the very end of the year (a bag of compost, for example) and the ones in pots get brought close to the house - just to keep the worst frosts off. Flowering season: July through to the first frosts. Buy and plant tubers around Mar/Apr.
Tulips are very reliable and will flower again next year, but often never as good as the first year. That means you end up adding more bulbs every 2-3 years to get a good display. Flowering season: March - May, depending on variety. Buy and plant bulbs around Oct/Nov.
Daffodil bulbs are as cheap as chips and are much more reliable about repeat flowering each year. Flowering season: Feb - April, depending on variety. Buy and plant bulbs around Sep/Oct.
Allium bulbs are also cheap (Purple Sensation, for eg) and will come back year after year. Flowering season: April - June. Buy and plant bulbs around Sep/Oct.
Chrysanths are cheap and will come back year after year. They need little care except cutting back in late spring to stop them getting too tall and leggy (some varieties) and then cutting back at the end of the year. Flowering season: August to winter. Buy and plant small plants around Apr/May.
Peonies are also fairly cheap bought as bare roots. They take a few years to establish and flower but are lovely. Buy and plant bare roots now for flowers in 2-3 years. Flowering season: around May/Jun.
Personally, although I love camelias I wouldn't bother. They can be picky about the time of day they get sun and the buds can easily be ruined or damaged by weather or wildlife. I've only ever found them a pain, tbh.
Hyacinths are easy and I like to buy the bulbs for the house, have them flower indoors and when the flowers have gone over add them into the garden to flower outside next year. Over the years, the stock keeps growing. If you want to plant bulbs straight into the garden then you normally buy and plant around Sep/Oct. Flowering season: Feb-Apr.