Hard to choose-- but these are ones for smaller gardens.
For Lettuce- go with a premix of greens and seed generously. Then just let it grow. Sow densely and you won't get any weeds. Mixed greens are in all catalogues and I haven't found one better than any other. Fedco is the cheapest across the board for seeds in my limited experience.
Also get a butter or bibb lettuce. I can't say I've had a bad one. They just need to be started early inside and then transplant a few of them in your garden. Nothing better.
Beets- Detroit Dark is a good beet- the bottoms are good-- but really the tops are great. So sow them somewhat heavily but then harvest the tops to eat when you thin them and then let the beets grow to whatever size you want. You can still eat the tops and bottoms. Again-- Fedco is my seed choice or Victory Seeds Garden. Any of the golden beets are good as well.
I love onions and shallots. Lots of companies are doing onion bunches this year. Johnny's and Vermont Bean Company are where I got mine. This way you can try something more unique like a Candy onion instead of just red/yellow/white. I think the Candy onions rock.
The coolest peppers I'm adding this year are these Mini-peppers. I got green/yellow/orange/chocolate- most from Totally Tomatoes. You can stuff them and eat them as an appetizer or just eat them in one bite! The best pictures of these peppers are from the Cooks Garden. Actually Cooks Garden is one heck of a catalogue and for picture lovers you won't be able to put it down. Though almost all the seeds are too pricey in my opinion, the catalogue is gorgeous and I did order 2-3 things that I couldn't find anywhere else. Like the baby orange peppers. They have the other baby pepper colors at Burpee's and Johnny's and Totally Tomatoes.
The Vermont Bean Catalogue has the best variety of dried beans and good pole beans. So I did get a purple Kentucky Wonder from them. I'm going with pole beans this year. I have the room and cattle panels for the beans and they are so much easier to pick when you have to pick for and hour at a time.
I love Seeds of Change for Tomatoes but they are also moving to more of their own tomatoes and discontinuing ones I really liked. But Victory Seeds Garden and Fedco have good tomato prices compared to Seeds of Change. I love the Amish Paste Tomato. I also love San Marzano's for sauce. Amana Orange is my orange tomato pick. I like Brown Berry and Chocolate Cherry tomatoes from Totally Tomatoes. I love the pineapple tomato and Lillian's Yellow heirloom for yellows. I fell in love with Red Calabash from Seeds of Change last year- its a smaller tomato that is like a mini beefsteak. Pink Brandywine tomatoes rock the world in terms of beauty and nothing could kill them-- they are so disease resistant and so I got about 10 other pink varieties similar to a pink Brandywine this year as I loved them last year. Victory Seeds Garden has lots of great information about rare and heirloom tomatoes. They are also small and I like to support them so they continue to stay in business.
Chard grows well in our region and in my soil for some reason or maybe it just did well with our crazy weather last year. So I love Bright Lights Chard developed by Fedco and they are the cheapest. Order the Bright Lights Chard now as it can run out and not be available anywhere as I found last year.
For potatoes, choose a fingerling potato. Go with a Banana fingering for a small garden. They are really cool potatoes. Again, I don't have a preference so go with Fedco for the best price.
That's it off the top of my head. If anyone has a specific veggie in mind-- let me know and I can give you my thoughts about that specific veggie for supplier and/or variety. I'm not an expert by any means, but I've now got enough experience that when I see Tango - I know it's a celery and Lincoln that it's a leek (though there is also an Abraham Lincoln tomato).
I'm venturing into more cut flowers this year.... so any advice-- send it my way! I did Zinnias last year and there were fabulous. So I'm trying things like Bachelor buttons, Calendula, Cleome, Cosmos, Nasturtium, Pansy, Poppy and Redbeckia. So far, I see the names on my list- but it will take me the summer to really remember the name with the flower.