I am not travelling as much as in previous year, but still try to visit some interesting places when I can. As it usually mean going abroad new sim cards are bought for such visits. Or not.
During last weeks I was in Germany, Iceland, USA and Canada. Needed Internet access in each of them but not everywhere that meant new sim card.
In Germany I am using ALDI Talk card which I bought few months ago. Cost was 12€ with 10€ credit on card. Internet access comes with 500MB data limit per day for 2€ and it usually covers my needs (it gets insanely slow after reaching limit).
Iceland was typical “one time use” card so I went for Nova as it was first available one. Costed one or two thousands ISK and gave me enough data for my 24h visit.
Then USA. Country where even prepaid is expensive. Bought T-Mobile sim card in 7/11 for 47USD including 35USD of credit of which 30USD went for 5GB data package. Getting card running requires registration with codes from starter kit. During 11 days of stay I used about 3GB of it. There were also huge amount of open wifi networks.
Canada was next on list. No sim card this time as 30CAD + 10CAD for 1GB of data was total rip-off. Living on open wifi networks sucks. With my next visit I wait until they got some sane prices ;D
How it looks in other countries?
Poland - buy any sim card in kiosk for 5PLN (1.25€), put into device and usually 1GB of data is available.
Czech Republic - last time I used O² with 375MB data package but do not remember price for it.
Belgium - 10€ on Lycamobile card (card available for free in shops) gave me 3GB data (for 7€).
Finland - Saunalahti card costs 4€ with 6€ credit. Maximum price for Internet access per day is 1.70€ so one card is fine for 3 days. Then you just buy next one or top up with minimum 10€.
I have also cards from UK, Hong Kong, Lithuania and Latvia but do not remember details any more. But all can be always checked on prepaid data sim card wiki.