Trinidad Perfume is fun. No heat at all but taste exactly like they should be hot - really nice flavour.
John's Super Long - quite hot and up to a foot long - fun to grow.
Bird's Eye - For that authentic SE Asian taste.
Padron - mild and great for stuffing.
Lemon Drop - Hot with a citrus taste
Biquinho - small, mild and fruity
Prairie Fire - small plants, quick to ripen and quite hot - good for indoors.
If you want something hot then try Carolina Reaper or Trinidad Scorpion. Too hot for me but good for adding heat to sauces.