I rate plenty of ASX shares as exciting investments that look like good buys today for 2025 and the long term due to their valuations and growth plans.

There are many shares in my portfolio that I'm glad I own, but I wouldn't say I'm excited about all of them. Some are steady, defensive stocks, and I appreciate their resilience.

But I'm very excited about the two ASX shares we'll look at in this article. I own one (with plans to buy more when I have available funds), and I'm thinking about adding the other top ASX growth share to my portfolio this year.

One taps into Southeast Asia's large potential, while the other delivers mission-critical software. Let's explore.

Tuas Ltd (ASX: TUA)

This is the most exciting ASX growth share in my portfolio, in my view. It is based in Singapore and has rapidly grown its presence in the country over the last few years.

The company recently announced its FY25 first quarter update at the annual general meeting (AGM), with active mobile subscribers rising 26.6% year over year to 1.11 million. This is a key revenue driver and suggests there could be significant revenue growth in FY25.

Tuas is the sort of business that can grow its profit margins as it scales. That was evident in FY24 with the operating profit (EBITDA) margin climbing to 42%, up from 36% in FY23. It achieved an EBITDA margin of 45.3% in the first quarter of FY25 and I think that margin can continue climbing in the coming years.

I believe the company can continue growing revenue and earnings for many years because I expect the company will expand to countries with much larger populations. Malaysia and Indonesia could be among the first two expansion markets.

Tuas could become a much bigger business in five and 10 years, which is why I'm excited about this ASX share.

TechnologyOne Ltd (ASX: TNE)

The second ASX share on my buy list in 2025 is TechnologyOne. I'd describe this company as one of the leading tech shares on the ASX.

TechnologyOne provides a software-as-a-service (SaaS) enterprise resource planning (ERP) solution that can be accessed from any device, anywhere, and is supposedly easy to use. Its clients include more than 1,300 businesses, government agencies, local councils and universities.

The ASX share aims to grow revenue from its existing client base by 15% each year. It's doing a great job, achieving 17% growth in FY24. The company also invests significantly in software development each year, helping unlock further revenue growth as customers purchase more products and modules.

TechnologyOne aims for at least $1 billion of annual recurring revenue (ARR) by FY30 — it reported $470.2 million of ARR in FY24. The company also thinks its profit before tax (PBT) margin can reach 35% in the coming years — in FY24 the PBT margin was 30%.

With the business expecting rising revenue and a growing profit margin, it could deliver significant net profit growth over the next five years. I'm excited by what it could achieve, particularly if it can gain further traction in the UK. FY24 UK ARR increased by 70%.

I believe it can become larger in FY25 and grow significantly over the rest of the decade.